鴉片窟[ahenkutsu] opium den
仙窟[senkutsu] enchanted cave
巣窟[soukutsu] den
洞窟[doukutsu] cave
貧民窟[hinminkutsu] slums

魔窟[makutsu] den of thieves
偏窟[henkutsu] eccentricity
理窟[rikutsu] theory
巌窟[gankutsu] cave

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