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

悪水[akusui] undrinkable water
井戸水[idomizu] well water
一衣帯水[ichiitaisui] (being separated only by a) narrow strip of water
一水[issui] current (of water)
溢水[issui] inundation

飲水量[insuiryou] amount of drinking
飲料水[inryousui] drinking water
烏の行水[karasunogyouzui] quick bath
雲水[unsui] itinerant priest
塩化水素[enkasuiso] hydrogen chloride

渇き[kawaki] thirst
渇く[kawaku] to be thirsty
渇水[kassui] water shortage
渇望[katsubou] craving
渇望者[katsubousha] desiring person

のどが渇く[nodogakawaku] to be thirsty
饑渇[kikatsu] hunger and thirst
涸渇[kokatsu] drying up
渇死[kasshi] dying of thirst
渇ごう[katsugyou] adoration