合図
あいず · aizu · JLPT N3 · noun
signal
🚦 合 match + 図 plan: a cue that gets everyone on the same plan. Aizu ≈ eyes
合 means to fit or match, and 図 means a plan or design. A 合図 is a cue that lines everyone up on the same plan at the same moment. Sound hook: aizu sounds like eyes, and you often give a signal with your eyes.
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.