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

下血[geketsu] bloody bowel discharge
壊血病[kaiketsubyou] scurvy
吸血[kyuuketsu] bloodsucking
吸血鬼[kyuuketsuki] vampire
給血[kyuuketsu] donation of blood

供血者[kyouketsusha] blood donor
凝血[gyouketsu] blood clot
血の巡りが悪い[chinomegurigawarui] dim-witted
血の巡りの悪い[chinomegurinowarui] dim-witted