预定
yūdìng · HSK 7
to schedule in advance
📅 预 (in advance) + 定 (to fix/set) = to fix something in advance, predetermine
预 carries the pre- sense (advance, beforehand); 定 means to settle, fix, or decide. Together they mean settling a thing ahead of time — the same compound used for booking or reserving in advance.
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.'