照合
しょうごう · shougou · JLPT N1 · noun
verification
照 — 昭 (bright) phonetic + 灬 (fire radical)
照 is a semantic-phonetic compound. The bottom 灬 is a variant of 火 'fire', giving the meaning of light or illumination, while 昭 'bright' on top supplies the sound 'zhào' and reinforces the brightness sense. It originally meant to shine light on something, later extending to 'reflect', 'photograph', and 'according to'.
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.