合間
あいま · aima · JLPT N1 · noun
time interval
⏸️ 合間 = 合 (join) + 間 (gap): the gap between two joined things
合 (ai) means join or fit, and 間 (ma) means space or pause. Together they name the short break between two activities, like the pause between two tasks.
合 — 乛 (lid/roof) + 口 (mouth)
Originally a pictograph of a lidded vessel — a cover (亼) closing over an opening (口) — giving the core sense of 'come together, join, fit.' From 'fit/match' it extended to 'combine, unite, agree' and to measure-word uses. The reading hé reflects this 'joining' meaning.