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

一念発起[ichinenhokki] being resolved to (do something)
引き起す[hikiokosu] to cause
縁起[engi] omen
喚起[kanki] arousal
起きる[okiru] to get up

起上る[okiagaru] to rise
起す[okosu] to raise
起こり得る[okoriuru] to be possible to occur
起る[okoru] to occur
起つ[tatsu] to rise up