Several parts combine into one character.

明 is one of the most beautifully transparent compound ideographs in the script: 日 (sun) + 月 (moon) = bright. The two brightest lights of the East Asian sky placed side by side. By compounding the day-light and the night-light, the character defines "brightness" through their union. Identical across 繁體 / 新字体 / 简体.

The meaning extends from physical light to abstract clarity: 説明 (shuōmíng / setsumei, to explain — "speak clearly"), 明白 (míngbai / meihaku, clear/obvious), 分明 (fēnmíng / funmei, distinct), 文明 (wénmíng / bunmei, civilization — "writing-bright"), 明智 (míngzhì / meichi, wise — "clear wisdom"). When 明 sits in a compound, expect either physical light or intellectual clarity.

Historical note: 明 (Míng / Min) was also the name of one of China's most influential dynasties (1368–1644). The Ming Dynasty named itself after this character — promising "an enlightened age". The English-language adjective "Ming" — Ming porcelain, Ming furniture — comes directly from this character.

Mandarin: míng, rising 2nd tone. 明天 (míngtiān, tomorrow — "the next bright day"), 明白 (míngbai, to understand), 说明 (shuōmíng, to explain), 明显 (míngxiǎn, obvious), 光明 (guāngmíng, brightness / hope). The "next day" semantic extension from "bright" → "next morning" is one of the cleanest space-time metaphors in the language.

Japanese: THREE on-readings, all common — メイ (mei, dominant) in 明確 (meikaku, clear), 説明 (setsumei, explanation), 文明 (bunmei, civilization); ミョウ (myō, Buddhist / older) in 明日 (myōnichi, tomorrow — formal); ミン (min) in 明朝 (Minchō, Ming Dynasty / Mincho typeface). Kun-readings: あか.るい (akarui, bright), あ.ける (akeru, to dawn / open), あきら.か (akiraka, evident), 明日 (irregular: ashita / asu, tomorrow — three different readings for the same word!).

Memory aid: sun on the left, moon on the right. The brightest pair of lights, side by side.