清濁
せいだく · seidaku · JLPT N1 · noun
evil
💧 Both share the water radical 氵: 清 = clear water, 濁 = muddy water
Clear water is pure (清) and muddy water is impure (濁), so the pair covers purity and impurity. In Japanese grammar, seidaku also names the voiceless vs voiced sound distinction.
清 — water 氵 + 青 (azure/blue-green, phonetic)
清 is a semantic-phonetic compound. The water radical 氵 gives the meaning—originally clear, unmuddied water—while 青 (qīng, azure) supplies the sound and reinforces the image of pure blue-green water. The sense later broadened from 'clear water' to 'clear, pure, clean' in general.