以后
yǐhòu · HSK 2
later
⏭️ 以 = by/with + 后 = behind/after → 'with what comes after' = later
以 means 'by means of' or 'using'; 后 means 'behind' or 'after' (spatially or temporally). Together they form a time-adverb meaning afterwards or in the future. Common companion: 以前 (yǐqián) = before.
以 — phonetic 㠯 (plow/tool) + 人 (person)
Originally a pictograph of a hand-held plow or tool (㠯), later combined with 人 (person) to suggest 'using' something. The core meaning 'to use' extended metaphorically to 'by means of', 'with', and 'because of'. In modern Chinese it functions mainly as a grammatical particle.
后 — 厂 cliff + 一 + 口 mouth
Originally depicted a ruler or sovereign issuing commands, showing a figure with a mouth giving orders. It came to mean 'queen' or 'empress.' In modern simplified Chinese, 后 also absorbed the meaning 'behind/after' from the traditional character 後, so context decides which sense applies.