定義
ていぎ · teigi · JLPT N1 · noun
definition
📏 定 (set, fix) + 義 (meaning) = fixing what a word means
定義 is 定 (decide, fix) + 義 (meaning, right sense). To 'fix the meaning' of a word is to state it precisely, which is exactly what a definition does.
定 — roof 宀 + 正 (correct/upright, phonetic)
Originally written with 宀 (roof) over 正 (upright/correct), suggesting a household settled and orderly under its roof. Over time 正 simplified to 㐬-like form at the bottom, and the meaning shifted from 'settled home' to the broader senses of 'fix, stable, decide.'