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

印鑑[inkan] stamp
印鑑証明[inkanshoumei] certification of official registration of a seal
鑑みる[kangamiru] to heed
鑑札[kansatsu] licence
鑑識[kanshiki] judgement

鑑賞[kanshou] appreciation (e.g. of art)
鑑定[kantei] judgement
鑑別[kanbetsu] discrimination
龜鑑[kikan] pattern
図鑑[zukan] illustrated reference book