界定
jièdìng · HSK 7
define
📏 界 boundary + 定 fix/set = fix the boundaries = to define
界 means border or boundary and 定 means to fix or settle; together they mean setting where something starts and stops — to define or demarcate. Sound: jièdìng, with jiè the same as in 边界 (border).
界 — field 田 + scope 介
界 combines 田 (field) as the semantic component with 介 (jiè) as the phonetic. The original sense referred to boundaries between fields, then broadened to any border, limit, or realm — yielding modern meanings like 'world' (世界) and 'boundary' (边界).
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.'