清潔
せいけつ · seiketsu · JLPT N3 · na-adj
clean
🧼 清潔 = clear + pure, so clean through and through
Both kanji have the water radical 氵 on the left. 清 (sei) means clear, as in clear water, and 潔 (ketsu) means pure or spotless. Clear plus pure gives seiketsu: hygienically clean.
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.