安全期[anzenki] safe period
暗黒期[ankokuki] eclipse period
一期[ichigo] one's life time
一期[ikki] one term
一期一会[ichigoichie] once-in-a-lifetime encounter (hence should be cherished as such)

一周期[isshuuki] period (in astronomy)
一定期間[itteikikan] fixed interval
延期[enki] postponement
延期になる[enkininaru] to be postponed
沖積期[chuusekiki] alluvial period

適わない[kanawanai] no match for
快適[kaiteki] pleasant
快適さ[kaitekisa] amenity
適う[kanau] to come true (wish)
適える[kanaeru] to grant (request, wish)

好適[kouteki] ideal
最適[saiteki] optimum
最適化[saitekika] optimization
素適[suteki] lovely
適確[tekkaku] precise