清らか
きよらか · kiyoraka · JLPT N1 · na-adj
clean
💧 清 (kiyo) = clear, pure + らか = adjective suffix, as in 朗らか (cheerful)
The kanji 清 means clear or pure. The suffix らか turns it into an adjective, the same way it works in 朗らか. Clear, unmixed water is a good anchor for this word.
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.