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

厳粛[genshuku] gravity
綱紀粛正[koukishukusei] eliminating corruption among government officials
自粛[jishuku] self-control
粛として[shukutoshite] quietly
粛学[shukugaku] school purge

粛軍[shukugun] army purge
粛殺[shukusatsu] withering
粛正[shukusei] regulation
粛清[shukusei] (political) purge
粛党[shukutou] cleaning up (political party)