之后
zhīhòu · HSK 4
after
⏰ 之后 = 之 (this/that) + 后 (after/behind)
之 is a classical particle meaning 'this/that', and 后 means 'behind' or 'after'. Together they form 'after that' or 'afterwards' — used to mark something happening later in time or positioned behind.
之 — foot 止 above ground line 一
Originally a pictograph of a foot (止) stepping forward from a baseline, meaning 'to go' or 'to proceed'. Over time the concrete 'going' sense faded, and 之 was borrowed as a grammatical particle marking possession ('of') or as a pronoun ('it'), which became its dominant use in Classical Chinese.
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.