瞬间
shùn jiān · HSK 7
moment
👁️⚡ 瞬 = blink (eye 目) + 间 = interval; the gap of one blink = a moment
瞬 carries the eye radical 目 and means to blink; 间 means interval or gap. Together they name the tiny span of a single blink, hence a fleeting moment or in a flash.
间 — gate 門 + sun 日 (originally moon 月)
Originally written 閒, showing the moon 月 shining through a gate 門 — the gap or space between the doors. The moon was later replaced by 日 (sun), giving the modern 间. The core meaning 'space/interval between' extended to time intervals, rooms, and the measure word for buildings.