Several parts combine into one character.

Phonetic-semantic compound: 咅 (a phonetic, derived from 立 + 口) + 阝 (the right-side variant of 邑 "town"). The encoded definition: "a section of a town" — abstracted to "any portion / division / department". Identical across 繁體 / 新字体 / 简体.

部 anchors organizational vocabulary across CJK languages — anything broken into divisions tends to use this character: 部分 (parts / portions), 部門 / 部门 (department), 部署 (post / department), 部隊 / 部队 (military unit), 部品 (components / parts).

Mandarin: bù, falling 4th tone. 部分 (bùfèn, part — a high-frequency abstract noun), 部门 (bùmén, department / sector), 部队 (bùduì, military unit), 部长 (bùzhǎng, minister — head of a 部 ministry), 全部 (quánbù, all / entire), 一部分 (yī bùfèn, a portion). 部 appears in basically every Chinese government ministry name: 教育部 (Ministry of Education), 外交部 (Ministry of Foreign Affairs).

Japanese: on-reading ブ (bu) for compounds — 部分 (bubun, part), 全部 (zenbu, all / everything — high-frequency word), 部品 (buhin, components / parts), 部活 (bukatsu, after-school club activity — central feature of Japanese student life), 文学部 (bungakubu, literature department). The Japanese 部活 culture — clubs for sports, music, art, etc., that students join at school for years — anchors the social structure of middle and high school in Japan, dramatized in countless coming-of-age anime.

Irregular reading: 部屋 (heya, "room") — combines 部 with 屋 in a fully irregular reading. Every Japanese learner memorizes 部屋 as one of the foundational early vocabulary words: my room (私の部屋 / watashi no heya).

Memory aid: a town with sections — divisions of a whole.