血清[kessei] serum
粛清[shukusei] (political) purge
真清水[mashimizu] pure water
清ます[sumasu] to clear
清む[sumu] to clear (e.g. weather)

清い[kiyoi] clear
清まる[kiyomaru] to be purified
清め[kiyome] purification
清める[kiyomeru] to purify
清らか[kiyoraka] clean

国粋[kokusui] national characteristics
国粋主義[kokusuishugi] nationalism
純粋[junsui] pure
純粋培養[junsuibaiyou] clean (pure) culture
粋人[suijin] man of the world

清粋[seisui] elegance
生粋[kissui] pure
精粋[seisui] purity
不粋[busui] no sense of refinement