Parts of the body

血 is a compound ideograph of striking simplicity: 皿 (a vessel / dish) with a single dot above it (a drop of blood). The picture documents an ancient ritual practice — the ceremonial vessel containing sacrificial blood used in oaths and treaties. The original Chinese term 歃血 (shàxuè, "to sip blood") referred to the ritual of swearing fidelity by drinking sacrificial blood from a shared vessel, a practice attested across pre-Han Chinese sources. The character preserves the religious gravity of blood as a sacred substance.

From this ritual origin, three semantic threads grew: blood as biological fluid, blood as commitment / oath, and blood as kinship / lineage.

Korean reading "hyeol." 血液 (hyeoraek, blood — formal medical term), 血壓 (hyeorap, blood pressure), 輸血 (suhyeol, blood transfusion), 血氣 (hyeolgi, "blood-energy" = vigor / hot-bloodedness, especially in youth), 血族 (hyeoljok, blood relatives / kinship), 血盟 (hyeolmaeng, blood oath / blood-sworn alliance). The full triad — medical, kin, oath — is alive in modern Korean.

Mandarin presents one of the most subtle 破音字 distinctions in everyday speech. xuè (4th tone) is the formal / written / scientific reading: 血液 (xuèyè, blood), 血压 (xuèyā, blood pressure), 血型 (xuèxíng, blood type). xiě (3rd tone) is the colloquial / spoken reading: 流血 (liúxiě, to bleed — said when you cut yourself), 血 alone in casual speech (xiě, often with diminutive 儿: 血儿 xiěr). The same character read formally as xuè or casually as xiě — one of the rare CJK examples where register alone distinguishes pronunciation.

Japanese on-reading ケツ (ketsu) — 血液 (ketsueki, blood), 血圧 (ketsuatsu, blood pressure), 輸血 (yuketsu, transfusion), 出血 (shukketsu, bleeding / hemorrhage). Kun-reading ち (chi) — 血 (chi, blood — everyday word), 血まみれ (chimamire, soaked in blood / bloody), 鼻血 (hanaji, nosebleed — note the rendaku from chi → ji). The Japanese saying 血は争えない (chi wa arasoenai, "blood cannot be argued with") means "you cannot deny your bloodline / heritage shows through." Like Korean, Japanese splits formal medical vocabulary (ketsu) from everyday usage (chi).

Memory aid: a single drop of blood above a sacrificial vessel — the ritual origin of the character.

皮 is a pictograph showing a hand (又, the right side of the character) holding a knife and stripping away an animal's hide. The oracle bone form clearly depicts the action of skinning. From this concrete butchery scene grew the abstract meaning: the result of stripping = the hide / skin / outer covering. By further extension, 皮 came to mean any surface, peel, rind, or outer layer — not just animal hide. As a radical, 皮 itself appears in characters like 皺 (zhòu, wrinkle), 疲 (pí, tired — exhausted "to the skin").

Korean reading "pi." 皮膚 (pibu, skin — medical / formal), 脫皮 (talpi, molting / shedding skin — used metaphorically for personal transformation), 毛皮 (mopi, fur), 樹皮 (supi, tree bark), 表皮 (pyopi, outer skin / epidermis — both anatomical and metaphorical for "surface appearance"), 皮革 (pihyeok, leather goods).

Mandarin pí, 2nd tone. 皮 (pí, skin / leather / surface), 皮肤 (pífū, skin), 脱皮 (tuōpí, to peel / molt), 肚皮 (dùpí, "belly skin" = the stomach exterior), 苹果皮 (píngguǒpí, apple peel). And the wonderfully colloquial 调皮 (tiáopí, "to play with skin / to dye-treat hide" → "mischievous / cheeky") — a top-frequency adjective for describing children's playful naughtiness in Chinese: 这个孩子很调皮 ("this kid is so cheeky").

Japanese on-reading ヒ (hi) — 皮膚 (hifu, skin — medical), 表皮 (hyōhi, epidermis), 脱皮 (dappi, molting). Kun-reading かわ (kawa) — 皮 (kawa, skin / peel / hide). Important homophone caution in Japanese: かわ also means "river" (written 川) — same kana sound, different kanji. Context distinguishes 皮 (kawa, peel) from 川 (kawa, river). Compounds: 毛皮 (kegawa, fur — note this mixes kun-reading 毛 ke + kun-reading 皮 kawa with rendaku to gawa).

Memory aid: a hand stripping away an animal's hide. From the action of skinning came the result (skin) and by extension all outer surfaces, peels, and rinds.

The traditional 腦 is a compound: 月 (flesh) + 𡿺 (a striking pictograph of an infant's skull with the soft fontanelle on top, hair growing through it). The original etymology was anatomically precise: the brain sits in the skull where a baby's soft spot is, where hair grows. The character documented exactly where this organ resides in the body. Japan simplified to 脳, Mainland China to 脑 — both replaced the elaborate 𡿺 with a simpler shape, but kept the core 月 (flesh) radical that anchors body-part characters.

Korean reading "noe." 頭腦 (dunoe, "head-brain" = brain / intellect — used in both anatomical and intellectual senses), 腦炎 (noeyeom, encephalitis), 腦死 (noesa, brain death — the legal definition central to Korean organ-donation policy), 腦電圖 (noejeondo, electroencephalogram), and the politically loaded 首腦 (sunoe, "head-brain" = head of state / leader — used for national leaders, as in jeongsanghoedam vs sunoebu chief leadership).

Mandarin nǎo, 3rd tone (simplified 脑). 头脑 (tóunǎo, brain / mind — same compound structure as Korean dunoe), 脑子 (nǎozi, brain — colloquial), 脑袋 (nǎodài, head — extremely casual). Most importantly, the modern Mandarin word for computer: 电脑 (diànnǎo, "electric brain") — a 1970s coinage that beautifully captures what a computer is. Compare to Japanese コンピューター (loanword) and Korean (loanword). Only Mandarin coined a native compound. By extension: 笔记本电脑 (bǐjìběn diànnǎo, notebook computer = laptop), 平板电脑 (píngbǎn diànnǎo, "flat-board electric brain" = tablet).

Japanese on-reading ノウ (nō) — 脳 (nō, brain), 頭脳 (zunō, brain / intellect), 脳波 (nōha, brain waves / EEG), 首脳 (shunō, head of state / leader — used identically to Korean), 脳裏 (nōri, "brain interior" = the back of one's mind, used in expressions like 脳裏に焼き付く "to be burned into one's memory"). 脳 has essentially no kun-reading; the on-reading nō dominates.

Memory aid: flesh (月) at the top of the body where the soft fontanelle and growing hair mark the position — the brain.

背 has one of the most etymologically rich derivations in CJK: 北 (now read as "north") on top + 月 (the "flesh" radical, used in body-part characters). But 北 itself originally depicted two people standing back-to-back — a pictograph of literal turning-away. From that "two backs" image, 北 came to mean "north" (because in ancient Chinese ritual orientation, you turned your back to the cold north when facing south to address subordinates). When the body-part meaning of "back" needed its own character, the original two-people image got 月 added as a meat radical, producing 背 = the body part of the back. So 北 and 背 share an ancient root: both depict turning the back, but one became geographical (north) and the other anatomical (back).

The "back" image then radiated outward semantically: back of body → behind / behind one's back → to turn one's back on / betray → to violate. Korean preserves this entire semantic chain: 背景 (baegyeong, "background" — what is behind), 背叛 (baeban, betrayal — turning the back on), 違背 (wibae, violation), 背後 (baehu, the rear / hidden hand behind), 腹背 (bokbae, "belly and back" — front and rear), 背中 (literally back-middle — used in Japanese for "back of body").

Mandarin presents another classic 破音字 (tone-shifting character) with semantic split. bèi (4th tone) covers the noun and the metaphorical extensions: 背景 (bèijǐng, background), 背诵 (bèisòng, "to back-recite" = to memorize / recite by heart — referring to the way memorized text is accessed without the page in front of you, "from behind"). bēi (1st tone) means "to carry on the back / shoulder a burden": 背包 (bēibāo, backpack — literally "back-bag"). Same character (in both traditional and simplified scripts), tone marks meaning.

Japanese on-reading ハイ (hai) — 背景 (haikei, background), 背後 (haigo, the rear / behind the scenes), 違背 (ihai, violation). Multiple kun-readings: せ (se, back / height — note Japanese uses 背 for both "back" and "height," so 背が高い (se ga takai) means "tall" referring to bodily stature), せなか (senaka, the literal back of the body — formed by adding 中 "middle"), そむく (somuku, "to turn one's back" = to defy / betray / disobey). The Japanese phrase 親に背を向ける (oya ni se o mukeru, "to turn one's back on parents") carries the same metaphorical betrayal sense as Korean and Chinese.

Memory aid: 北 (two figures back-to-back) plus 月 (flesh) — the part of the body that turns away.

骨 is a compound ideograph: 冎 (a stylized depiction of bones — recognizable as skull and vertebrae stacked together) on top, plus 月 (the flesh radical) below. The combination reads as "the hard structure embedded within flesh" — bone. As a radical, 骨 itself anchors a small but vivid family: 髄 (suǐ, marrow), 骸 (hái, skeleton / corpse), and historically 體 (the traditional form of "body," etymologically "the abundance of bones"). Bones are conceived in Chinese tradition as the body's essential framework.

Korean reading "gol." Saturates anatomical and metaphorical vocabulary: 骨格 (golgyeok, skeleton / framework — used both anatomically and architecturally), 骨折 (goljeol, bone fracture), 骨髓 (golsu, bone marrow), 骨董品 (goldongpum, antique — literally "bone-collected piece," referring to objects so old their substance is bone-like), 遺骨 (yugol, remains / ashes of the deceased), 氣骨 (gigol, "spirit-bones" = backbone / strength of character). The metaphorical extension "bone → essential framework / strength of character" runs across all CJK languages.

Mandarin gǔ, 3rd tone. 骨 (gǔ, bone), 骨头 (gǔtou, "bone-head" = bone — colloquial), 骨骼 (gǔgé, skeleton), 骨干 (gǔgàn, "bone-stem" = backbone / core member of an organization), 骨折 (gǔzhé, fracture). The metaphor 骨干 ("bone-stem" = key personnel / structural backbone) is identical in feel to Korean golgyeok / gigan.

Japanese on-reading コツ (kotsu) — 骨折 (kossetsu, fracture, with the doubled consonant from sandhi), 骨格 (kokkaku, skeleton), 骨髄 (kotsuzui, bone marrow), 遺骨 (ikotsu, cremated remains — central to Japanese funerary practice; the bones picked up with chopsticks after cremation are called 骨上げ kotsuage). Kun-reading ほね (hone, bone) — 骨 (hone), 骨組み (honegumi, framework / structure), and the lovely idiom 骨折る (honeoru, "to break one's bones" = to take great pains / work hard at something). 骨を惜しまない (hone o oshimanai, "not to spare one's bones") means "to spare no effort." Japanese has a particular fondness for using 骨 as the metaphor for diligent labor.

Memory aid: 冎 (bone shape on top) plus 月 (flesh below) — the hard structure inside the soft tissue.

脈 is a semantic compound: 月 (flesh radical) + 𠂢 (a stylized branching shape, "tributaries / branches"). The character pictures "branching flows inside the body = blood vessels, the pulse." From this anatomical root, 脈 extended metaphorically to "any branching trunk-like thing" — mountain ranges, family lineages, narrative threads, professional networks. One of the most productive metaphor-engines in CJK vocabulary.

Korean reading "maek." 脈搏 (maekbak, pulse — medical), 動脈 (dongmaek, artery), 靜脈 (jeongmaek, vein), 山脈 (sanmaek, mountain range), 人脈 (inmaek, "people-veins" = personal network / connections), 文脈 (munmaek, "text-veins" = context / narrative thread). Inmaek in Korean business culture is a serious career concept — building one's inmaek across companies, schools, and hometowns is treated as a measurable professional asset.

Mandarin mài, 4th tone. Simplified form 脉 — 脉 (mài), 脉搏 (màibó, pulse), 静脉 (jìngmài, vein), 人脉 (rénmài, personal connections / network), 山脉 (shānmài, mountain range). Identical metaphorical reach to Korean. 人脉 dominates Chinese business-school vocabulary as the explicit name for what English calls "networking."

Japanese on-reading ミャク (myaku) — no kun reading in common use. 脈 (myaku, pulse), 脈拍 (myakuhaku, pulse rate), 動脈 (dōmyaku, artery), 人脈 (jinmyaku, personal network — major Japanese business term: 人脈を作る jinmyaku o tsukuru, "to build connections"), 山脈 (sanmyaku, mountain range). Japanese corporate culture treats 人脈 as a measurable career asset, much like LinkedIn-era Western "network" — but with longer cultural roots, since the metaphor itself is 2,000 years old.

Memory aid: flesh (月) plus a branching flow (𠂢) — the body's branching streams, then any branching trunk in the world.

筋 is a triple-component compound ideograph — unusual in CJK characters, where most have only two main parts. Three radicals contribute: ⺮ (bamboo) on top, 月 (flesh) on the lower left, 力 (power / force) on the lower right. The composite picture is rich: bamboo-like grain (the striated structure of muscle fibers, which split lengthwise like bamboo) + flesh + power = sinew / muscle / tendon. Each component carries a piece of the meaning. The "bamboo grain" metaphor is anatomically apt — muscle fiber bundles do separate along grain lines, like bamboo.

Korean reading "geun." 筋肉 (geunyuk, muscle), 筋力 (geunnyeok, muscular strength), 腹筋 (bokgeun, abdominal muscles / abs — central to Korean fitness vocabulary), 心筋 (simgeun, cardiac muscle / myocardium), 鐵筋 (cheolgeun, "iron-sinew" = rebar / steel reinforcement bars in concrete construction). Important homophone caveat: the Korean syllable geun represents many unrelated Hanja — 根 (root), 近 (near), 勤 (diligent), 筋 (muscle) — each with completely different etymologies.

Mandarin jīn, 1st tone. 筋 (jīn, muscle / tendon), 筋肉 (jīnròu, muscle), 脑筋 (nǎojīn, "brain-muscle" = mind / thinking — Mandarin uses this metaphor more freely than Korean or Japanese; 动脑筋 dòng nǎojīn = "to use one's brain muscle" = to think hard), 钢筋 (gāngjīn, "steel-sinew" = rebar — same construction metaphor as Korean cheolgeun).

Japanese on-reading キン (kin) — 筋肉 (kin'niku, muscle), 腹筋 (fukkin, abdominal muscles), 心筋 (shinkin, cardiac muscle), 筋肉痛 (kinnikutsū, muscle soreness — extremely common after exercise). Kun-reading すじ (suji) — and here Japanese took the character's metaphorical capacity to an unusual degree. すじ means "tendon / line / streak / stripe," but also "plot of a story / logical line of reasoning / ancestry / source." 話の筋 (hanashi no suji) = "the plot / thread of a story." 筋道 (sujimichi) = "line of reasoning / logic." 筋がいい (suji ga ii) = "has good aptitude / good lineage / promising bloodline." The single Japanese word suji unifies physical sinew, narrative thread, and logical structure — a remarkable semantic web.

Memory aid: bamboo grain (⺮) + flesh (月) + power (力) — striated, fleshy, force-producing tissue.

胸 is a phonetic-semantic compound: 月 (the "flesh" radical for body parts) + 匈 (xiōng, originally itself a pictograph of the chest). The character has a fascinating bifurcation history: the original 匈 once meant "chest," but historical drift redirected 匈 to a new meaning — "the Xiongnu," the nomadic peoples of the Eurasian steppe who threatened Han dynasty China (recorded as 匈奴, Xiōngnú). Once 匈 was occupied by an ethnonym, the body-part meaning needed disambiguation, so the flesh radical 月 was added to create 胸 specifically for "chest." This is a rare and instructive case of one character splitting into two distinct characters when an etymological ambiguity demanded resolution.

The character carries a beautiful semantic extension across all three CJK languages: from the literal chest cavity (the body) → the seat of feeling (the heart and mind). Almost universally, "what is in the chest" became "what one feels and thinks."

Korean reading "hyung." 胸部 (hyungbu, chest — medical), 胸圍 (hyungwi, chest measurement / bust size), 胸像 (hyungsang, bust statue / a sculpture from the chest up), 胸襟 (hyunggeum, "chest robe" = inner feelings / the depth of one's heart). The Korean phrase (hyunggeum-eul teonota, "to open the depth of one's chest") is a deeply Korean way to express "to speak openly from the heart."

Mandarin xiōng, 1st tone. 胸 (xiōng, chest), 胸口 (xiōngkǒu, "chest mouth" = the pit of the stomach / solar plexus), 胸怀 (xiōnghuái, "chest-bosom" = breadth of mind / aspirations / one's inner state — used in expressions of leadership and vision: 胸怀大志 xiōnghuái dàzhì, "to bear great aspirations in the chest"), 胸罩 (xiōngzhào, "chest-cover" = brassiere — modern medical/colloquial term). The metaphorical extension to mental capacity is perhaps strongest in Mandarin.

Japanese on-reading キョウ (kyō) — 胸部 (kyōbu, chest — medical), 胸囲 (kyōi, chest circumference). Kun-reading むね (mune) — 胸 (mune, chest / heart), 胸が痛い (mune ga itai, "my chest hurts" — used both literally for physical pain and emotionally for heartbreak). The compound 胸騒ぎ (munasawagi, "chest-disturbance" = an uneasy feeling, foreboding, premonition) is one of the most evocative Japanese emotional vocabulary items — capturing the exact bodily sensation of dread or anticipation. Note the alternative kun-reading むな (muna) used only as a prefix in compounds: 胸毛 (munage, chest hair), 胸元 (munamoto, the area at the base of the throat).

Memory aid: 月 (flesh) plus 匈 (originally chest, now means Xiongnu people) — body-part disambiguation forced the addition of the flesh radical.

肝 is a phonetic-semantic compound: 月 (flesh) + 干 (gān, "shield" — providing the sound). What makes 肝 culturally rich is that traditional East Asian medicine assigned the liver an extraordinary metaphysical role: the liver was considered the body's shield against external attack, the seat of the spirit, and crucially the seat of courage and decisiveness. The very phonetic 干 ("shield") embeds this conception. From this medical-philosophical framework, 肝 took on a second meaning across all CJK languages: not just the organ, but bodily courage / nerve / mettle. The English idiom "to have guts" maps almost exactly onto the CJK use of liver-as-courage.

Korean reading "gan." 肝臟 (ganjang, liver — anatomical), 肝炎 (ganyeom, hepatitis), 肝硬變 (gangyeongbyeon, cirrhosis), and the literarily charged 肝膽相照 (gandam-sangjo, "liver and gallbladder reflecting each other" — a Tang-era idiom for sincere friendship where two people share their innermost feelings). Korean colloquial: ("the liver is big") = bold / brave; ("the liver is small") = cowardly / timid. The Korean compound (ganjang) homophonically also means "soy sauce" — same hangeul, different etymology.

Mandarin gān, 1st tone. 肝 (gān, liver), 肝脏 (gānzàng, liver — anatomical), 肝炎 (gānyán, hepatitis), 肝胆 (gāndǎn, "liver and gallbladder" = courage / heart-and-soul). And the affectionate 心肝 (xīngān, "heart-liver") used as a term of endearment for one's most beloved — child, lover, or grandchild: 心肝宝贝 (xīngān bǎobèi, "heart-liver treasure-baby") is what a Chinese grandmother might call her favorite grandchild. The "vital organs" become metaphors for what is most precious.

Japanese on-reading カン (kan) — 肝臓 (kanzō, liver — medical), 肝炎 (kan'en, hepatitis), 肝心 (kanjin, "liver-heart" = the most important / crucial — note the same metaphorical leap as Korean / Chinese, where vital organs = essential matters). Kun-reading きも (kimo) is wonderfully versatile — 肝 (kimo, liver / guts / core / essence). Idioms cluster around the courage meaning: 肝が据わる (kimo ga suwaru, "the liver settles in place" = to become composed and brave), 肝試し (kimodameshi, "test of liver" = a test of courage, especially the Japanese summer tradition of nighttime visits to haunted places, popular among schoolchildren and dating couples), 肝に銘じる (kimo ni meijiru, "to engrave on the liver" = to take deeply to heart). Japanese keeps liver-as-courage as a living metaphor more vividly than any other CJK language.

Memory aid: flesh (月) + shield (干) — the organ that shields the body and houses courage.

腸 is a phonetic-semantic compound: 月 (flesh, for body parts) + 昜 (yáng, originally a pictograph of sunlight rays extending in long, radiating beams — providing both the sound and a hint of "long, extended" meaning). The composite captures the body part precisely: a long, extended tube within the body — the intestines. The phonetic component 昜 anchors a beautiful family of "long-extended" characters: 場 (chǎng, open field / arena), 陽 (yáng, sun / yang principle), 楊 (yáng, willow tree — known for long drooping branches). All share the long-extended visual signature. Mainland China simplified to 肠.

Korean reading "jang." 大腸 (daejang, large intestine), 小腸 (sojang, small intestine), 腸炎 (jangyeom, enteritis / intestinal inflammation), 胃腸 (wijang, "stomach and intestines" = the digestive tract collectively), and the literarily charged 斷腸 (danjang, "broken intestines" = unbearable grief / heartbreak so severe it feels like the gut is being torn apart). The compound 斷腸 (Mandarin duàncháng, Japanese danchō) appears across CJK literature as the supreme metaphor for emotional anguish — used famously in classical Chinese poetry and reborn in modern song titles like Teresa Teng's 斷腸紅 ("Crimson of Broken Intestines"). Few somatic metaphors carry as much literary weight.

Mandarin cháng, 2nd tone (simplified 肠). 大肠 (dàcháng), 小肠 (xiǎocháng), 肠炎 (chángyán, enteritis), and the delightfully literal 香肠 (xiāngcháng, "fragrant intestines" = sausage). Western sausages, when translated into Mandarin, became "fragrant intestines" — a description that is anatomically accurate (sausage casing is intestine) and mouth-wateringly direct.

Japanese on-reading チョウ (chō) — 腸 (chō, intestine), 大腸 (daichō, large intestine), 小腸 (shōchō, small intestine), 胃腸 (ichō, gastrointestinal tract), 大腸炎 (daichōen, colitis). The kun-reading はらわた (harawata, "guts / innards") survives but is largely literary or archaic — modern Japanese medical and conversational use defaults to the on-reading chō.

Memory aid: flesh (月) plus 昜 (long extended sunbeams) — the long extended tube inside the body.

胃 is a semantic compound: 田 on top (originally a pictograph of a sack of grain — not actually "field" here) + 月 (flesh radical) below. The composite literally pictures: "a grain-sack inside the body = stomach." A rare case where Chinese etymology drew an organ exactly by its function — the stomach as the body's grain-holding pouch, sketched in seal script as a small bag dangling above flesh.

Korean reading "wi." 胃腸 (wi-jang, stomach and intestines / digestive system), 胃酸 (wi-san, stomach acid), 胃癌 (wi-am, stomach cancer), 健胃 (geon-wi, "to strengthen the stomach" — a category in traditional Korean medicine and on Korean digestive-aid product labels), 胃炎 (wi-yeom, gastritis). Korean medical Korean uses 胃 universally.

Mandarin wèi, 4th tone. 胃 (wèi), 胃口 (wèikǒu, "stomach-mouth" = appetite — daily idiom), 胃疼 (wèiténg, stomach ache), 胃癌 (wèi'ái, stomach cancer). The compound 胃口 deserves attention: it is the Chinese way to say "I have an appetite for that" or "that whets my appetite." Mandarin reads body-state through the stomach rather than the brain — 我对这个没胃口 (wǒ duì zhège méi wèikǒu) = "I have no appetite for this" = "I'm not interested in this," a metaphorical reach you don't hear in Korean or Japanese.

Japanese on-reading イ (i) — no kun reading in common use. 胃 (i, stomach — the bare character is itself a daily word in Japanese), 胃腸 (ichō, stomach and intestines), 胃癌 (igan, stomach cancer), 胃酸 (isan, stomach acid). The single-character reading 胃 (i) appears as the prominent banner in Japanese pharmaceutical advertising for any stomach medicine — TV commercials with the giant red character い are a Japanese cultural staple that anyone who has watched 30 seconds of Japanese television will recognize.

Memory aid: a grain-sack (田) above flesh (月) — the body's pouch for what we eat.

肺 is a phonetic-semantic compound: 月 (the "flesh" radical for body parts) + 巿 (fú, originally a depiction of branching, drooping plant tendrils — providing both the sound and a visual hint of branching anatomy). Critical visual caution: the right component 巿 looks almost identical to 市 (shì, "market") but differs by a single feature — in 巿, a vertical stroke passes straight through the top, whereas 市 has a separate dot above. Confusing the two is one of the most common kanji-recognition errors for learners.

Korean reading "pye." 肺活量 (pyehwallyang, lung capacity / vital capacity), 肺癌 (pyeam, lung cancer), 肺炎 (pyeryeom, pneumonia), 肺結核 (pyegyeolhaek, pulmonary tuberculosis), 心肺 (simpye, "heart-lung" = cardiopulmonary, used in simpyesosaengsul cardiopulmonary resuscitation). Pye saturates Korean medical terminology.

Mandarin fèi, 4th tone. 肺 (fèi, lung), 肺炎 (fèiyán, pneumonia — became globally familiar through the COVID-era term 新型冠状病毒肺炎 "novel coronavirus pneumonia"), 肺癌 (fèi'ái, lung cancer), 心肺 (xīnfèi, cardiopulmonary), 肺活量 (fèihuóliàng, lung capacity). The vocabulary parallels Korean almost exactly.

Japanese on-reading ハイ (hai) — 肺 (hai, lung), 肺活量 (haikatsuryō, lung capacity — measured in fitness tests during Japanese school physical education), 肺炎 (haien, pneumonia), 心肺 (shinpai — note this homophone with 心配 shinpai meaning "worry"; context disambiguates). 肺 has essentially no kun-reading in modern Japanese; the on-reading ハイ covers everyday medical and anatomical use.

Memory aid: flesh (月) plus 巿 (drooping branching tendrils) — the branching internal organ that fills with air. Distinguish 巿 from 市 (market) by checking the top stroke.

牙 is a pictograph of "two teeth biting each other at an angle" — an oracle-bone character resembling a sideways "ヲ" shape, depicting the interlock of upper and lower molars. 牙 pairs with 齒 (chǐ, "incisors / a row of front teeth"): 齒 = the row of front teeth visible when smiling, 牙 = the back molars or animal fangs. A division of labor inside CJK's tooth vocabulary.

Korean reading "a." 象牙 (sang-a, ivory — literally "elephant-tooth"), 齒牙 (chi-a, teeth — formal medical Korean), 牙城 (a-seong, "fortress of fangs" = a stronghold / power base). 牙城 is a vivid Korean expression that turns a wild animal's lair into a political concept — Korean newspaper headlines use ("the conservative stronghold") as a stock phrase for entrenched political bases.

Mandarin yá, 2nd tone. 牙 (yá, tooth — daily), 牙齿 (yáchǐ, teeth), 牙刷 (yáshuā, toothbrush), 牙膏 (yágāo, toothpaste), 象牙 (xiàngyá, ivory). Mandarin uses 牙 as the everyday word for "tooth" — and this is one of the most striking divergences in shared CJK script: Korean uses Hangul i, Japanese uses 歯 (ha), Mandarin uses 牙. Three different daily words for the same body part across three cultures that share the writing system.

Japanese on-readings ガ (ga) and ゲ (ge) — 象牙 (zōge, ivory), 歯牙 (shiga, tooth — formal). Kun-reading きば (kiba) — but here Japanese makes a sharp distinction: 牙 (kiba) means specifically "fang / animal tooth," not human tooth. 狼の牙 (ōkami no kiba, "the wolf's fang") is a stock phrase in Japanese folklore. Japanese reserves 牙 (kiba) for animal teeth and uses 歯 (ha) for human teeth — a distinction the daily Mandarin word 牙齿 collapses entirely.

Memory aid: three CJK languages, three different everyday words for "tooth" — Korean i, Japanese 歯, Mandarin 牙 — a vivid case where shared writing diverges into completely different daily speech.

唇 is a phonetic-semantic compound: 辰 (chén, "5th of 12 zodiac branches / morning hours / shellfish-like" — providing the sound) + 口 (mouth). The composite reads as "the soft flesh spread around the mouth" = lips. The phonetic 辰 has a complex history (its original meaning was a kind of clam/shellfish), but here it serves only as the sound component, with the meaning carried by 口.

Korean reading "sun." Korean uses 唇 strictly in medical and linguistic contexts: 口脣 (guseun, lips — anatomical / medical), 脣音 (suneum, "lip-sound" = labial consonant — phonological term used in linguistics: ㅁ, ㅂ, ㅍ are suneum in Korean), 朱脣 (juseun, "vermilion lips" — classical literary term for beautiful red lips, used in poetry). Modern Korean overwhelmingly uses native (ipsul) for everyday "lips."

Mandarin chún, 2nd tone. 唇 (chún), 嘴唇 (zuǐchún, "mouth-lips" = lips — the everyday compound, since 嘴 covers "mouth" colloquially), 唇膏 (chúngāo, "lip-paste" = lipstick), 唇齿 (chúnchǐ, "lips and teeth" — used in idiom 唇亡齿寒 chúnwáng chǐhán "when lips are gone, teeth feel cold" = mutual interdependence between two parties; classic Chinese geopolitical metaphor). 双唇音 (shuāngchúnyīn, bilabial consonant) — phonology vocabulary.

Japanese on-reading シン (shin) is almost unused. The kun-reading くちびる (kuchibiru, "lips") dominates: 唇 (kuchibiru), 上唇 (uwakuchibiru, upper lip), 下唇 (shitakuchibiru, lower lip — sometimes shitakuchibira). The Japanese cosmetic term 口紅 (kuchibeni, "mouth-red") for lipstick uses different kanji but the concept overlaps. Japanese idiom 唇を噛む (kuchibiru o kamu, "to bite the lip") = "to suppress strong emotion / hold back from crying or speaking out" — universal across CJK.

Memory aid: mouth (口) plus 辰 (sound) — the soft flesh framing the mouth = lips.

膝 is a phono-semantic compound: 月 (the flesh radical, marking it as a body part) + 桼 (qī, "lacquer tree" — phonetic). 桼 lent the sound; 月 carried the meaning. Composite reading: "the rounded fleshy joint of the leg = knee." The flesh radical 月 (a stylized 肉) anchors the entire CJK body-part vocabulary.

Korean reading "seul." 膝下 (seul-ha, "below the knees" = at one's parents' side — a literary expression for being raised by one's parents and used in formal Korean to indicate one's family origin), 膝關節 (seul-gwanjeol, knee joint — medical). 膝下 still appears in dignified Korean prose as a formal way to refer to the place and parents that raised a person.

Mandarin xī, 1st tone. 膝 (xī), 膝盖 (xīgài, knee — daily), 跪膝 (guìxī, kneeling). 膝盖 dominates everyday Chinese — "I scraped my knee" in Mandarin is 我膝盖擦破了 (wǒ xīgài cā pò le), with 膝盖 ("knee-cap") rather than the bare 膝.

Japanese on-reading シツ (shitsu) — 膝関節 (shitsukansetsu, knee joint — medical). Kun-reading ひざ (hiza) — 膝 (hiza, knee), 膝枕 (hizamakura, "knee-pillow" = lying with one's head on someone's lap). 膝枕 is one of the most beloved Japanese pop-culture tropes — manga, anime, and live-action drama have built thousands of intimate scenes around the image, to the point where the word itself carries strong emotional and romantic weight.

Memory aid: flesh (月) plus the phonetic 桼 — the rounded fleshy hinge of the leg.

腎 is a phono-semantic compound: 臤 (qián, "firm / hard" — itself a compound of 臣 "subject" + 又 "hand," giving the image of "firmly grasping") + 月 (flesh radical). 月 carries the meaning; 臤 lends both sound and a secondary connotation: "the firmly-set organ inside the body = kidney." East Asian traditional medicine treats 腎 as the seat of vital essence (精) and life force — a far broader concept than the Western anatomical kidney, encompassing reproductive vitality, deep stamina, and longevity.

Korean reading "shin." 腎臟 (shinjang, kidney — medical), 腎不全 (shin-bujeon, kidney failure), 副腎 (busin, adrenal gland — literally "secondary kidney"), 腎結石 (shin-gyeolseok, kidney stone). All medical Korean. Traditional Korean medicine (hanuihak) uses 腎 with the broader life-essence meaning, prescribing (bo-shin-tang, "kidney-tonifying soup") as a well-known summer-stamina dish.

Mandarin shèn, 4th tone. Simplified form 肾 — 肾 (shèn), 肾脏 (shènzàng, kidney), 肾炎 (shènyán, nephritis), 肾结石 (shènjiéshí, kidney stone). Identical medical vocabulary to Korean. Chinese traditional medicine retains the broader 腎 = "vital essence" reading especially in the phrase 补肾 (bǔ shèn, "to tonify the kidney") — a category of herbal supplements explicitly aimed at male sexual vitality and deep energy.

Japanese on-reading ジン (jin) — no kun reading in common use. 腎臓 (jinzō, kidney), 腎不全 (jinfuzen, kidney failure), 副腎 (fukujin, adrenal gland). Japanese medical vocabulary tracks the Korean and Chinese forms almost word-for-word — one of the most consistent CJK technical vocabularies, since modern medicine adopted these compounds together in the late 19th century.

Memory aid: 臤 ("firmly grasping") plus flesh (月) — the firm organ that holds the body's vital essence.

喉 is a phono-semantic compound: 口 (mouth — meaning) + 候 (hóu, "to wait / await" — phonetic). 候 lent its sound, 口 carried the meaning. Composite reading: "the inner passage of the mouth = throat." A textbook example of how phonetic radicals work in Chinese characters.

Korean reading "hu." 喉頭 (hudu, larynx — medical), 喉音 (hueum, "throat sound" = a guttural consonant in phonetics), 咽喉 (inhu, throat — formal medical compound), 喉痛 (hutong, throat pain). All medical or technical Korean — the everyday Korean word for "throat" stays Hangul (mokgumeong).

Mandarin hóu, 2nd tone. 喉咙 (hóulóng, throat — daily speech), 喉头 (hóutóu, larynx), 咽喉 (yānhóu, throat — formal/medical). 喉咙 dominates everyday Mandarin — a Chinese speaker with a sore throat says 我喉咙痛 (wǒ hóulóng tòng), almost never the bare 喉.

Japanese on-reading コウ (kō) — 喉頭 (kōtō, larynx), 咽喉 (inkō, throat — medical). Kun-reading のど (nodo) — 喉 (nodo, throat — daily), 喉が痛い (nodo ga itai, "my throat hurts"). Japanese has a folk-medical compound 喉風邪 (nodo-kaze, "throat-cold" — a cold that began with throat soreness) that anchors an entire shelf of over-the-counter Japanese pharmacy products.

Memory aid: mouth (口) plus the phonetic 候 — the inner mouth-passage where breath waits before becoming voice.

肘 is a semantic compound: 月 (flesh radical) + 寸 (cùn, "inch / a hand's-breadth"). 寸 originally pictured "the joint just below the wrist" — the body's natural unit of measurement. So the etymology is unusually precise: "the joint of the arm at the body's measurement point = elbow." A character whose construction maps directly to anatomy.

Korean reading "ju." 肘關節 (ju-gwanjeol, elbow joint — medical). Very narrow Korean usage — the Hangul word (palkkumchi) dominates daily speech, and 肘 appears almost only in anatomy textbooks and acupuncture-meridian charts.

Mandarin zhǒu, 3rd tone. 肘 (zhǒu, elbow — daily), 肘子 (zhǒuzi, elbow — but also "pork hock / pig knuckle" in cooking contexts). The cooking sense is alive across Chinese menus: 红烧肘子 (hóngshāo zhǒuzi, braised pork hock) is a banquet staple where the cut's name comes directly from its anatomical position on the pig.

Japanese on-reading チュウ (chū) — almost never used. Kun-reading ひじ (hiji) — 肘 (hiji, elbow — daily), 肘掛け (hijikake, armrest — common in furniture vocabulary), 肘鉄砲 (hijiteppō, "elbow gun" = an elbow-jab to refuse advances — a slangy Japanese phrase for rejecting a romantic approach: 肘鉄を食らう, "to be hit with the elbow gun" = "to be rejected").

Memory aid: flesh (月) plus the inch-mark (寸) — the body part at the arm's measuring joint.

顎 is a phonetic-semantic compound: 頁 (the "head / page" radical, which despite the modern "page" meaning originally depicted a head and is used in characters for facial features) + 咢 (è, "startled cry" — providing the sound). The composite reads as "the lower part of the head" = jaw. The 頁 radical anchors all face-and-head anatomy in CJK: 顔 (face), 頭 (head), 額 (forehead), 頰 (cheek), 顎 (jaw), 頸 (neck). Mainland simplified to 颚.

Korean reading "ak." 上顎 (sangak, upper jaw / maxilla — anatomical), 下顎 (haak, lower jaw / mandible), 顎關節 (akgwanjeol, temporomandibular joint — TMJ, the jaw joint that often causes problems and is discussed in Korean dental health contexts). Korean uses ak strictly in medical and dental terminology; everyday "jaw" is the native teok.

Mandarin è, 4th tone (simplified 颚). 上颚 (shàng'è, upper jaw), 下颚 (xià'è, lower jaw), 颚骨 (ègǔ, jawbone). Modern Mandarin uses these in medical and zoological contexts; everyday speech for "chin / jaw" is 下巴 (xiàba).

Japanese on-reading ガク (gaku) — 上顎 (jōgaku, upper jaw), 下顎 (kagaku, lower jaw — formal medical term). Kun-reading あご (ago) is the everyday Japanese word for jaw / chin. The Japanese idiom 顎が落ちる (ago ga ochiru, "the jaw falls off") means "to be astonishingly delicious" — a vivid expression for food so good your jaw drops in awe. Used in food reviews: あごが落ちるほど美味しい ("delicious enough to drop your jaw"). Another: 顎で使う (ago de tsukau, "to use someone with the jaw") = "to order someone around imperiously" — the gesture of pointing with the chin to dismiss or command.

Memory aid: head-radical (頁) plus 咢 (sound) — the part of the head where the lower part hinges = jaw.

髭 is a phono-semantic compound: 髟 (the long-hair radical, indicating any hair-like growth) + 此 (cǐ, "this" — phonetic). 此 lent the sound, 髟 carried the meaning. Specifically: hair growing above the mouth = mustache. CJK distinguishes three beard zones with three different characters — 鬚 (chin beard), 髭 (mustache), 髯 (sideburns) — a level of facial-hair vocabulary granularity that English entirely lacks.

Korean reading "ja." Almost a dead character in modern Korean — the Hangul word (suyeom) covers all beard zones, and 髭 appears only in dictionaries and classical texts. A Korean asked to read 髭 will often pause before producing the sound.

Mandarin zī, 1st tone. 髭 itself appears almost exclusively in literary Chinese; everyday Mandarin uses 胡子 (húzi, "the beard / mustache" — generic) for the general concept and 小胡子 (xiǎohúzi, "small beard" = mustache) for the specific. The 子 suffix turns the body-part into a casual everyday noun — a grammatical move Mandarin loves.

Japanese on-reading シ (shi) — almost never used. Kun-reading ひげ (hige) — 髭 (hige, mustache), 髭剃り (higesori, shaving). Modern Japanese sometimes writes all three beard-zone characters (鬚, 髭, 髯) with the same kun reading ひげ, distinguishing them only through which character is written — when a Japanese person says "hige" out loud, only context tells you which beard zone.

Memory aid: hair (髟) plus "this" (此, phonetic) — "this hair, right here above the mouth."