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

簡潔[kanketsu] brevity
潔よい[isagiyoi] manly
潔白[keppaku] innocence (i.e. not guilty)
潔癖[keppeki] fastidiousness
高潔[kouketsu] purity

純潔[junketsu] purity
清潔[seiketsu] clean
清廉潔白[seirenkeppaku] being upright and cleanhanded
貞潔[teiketsu] chastity
不潔[fuketsu] unclean