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

見澄ます[misumasu] to observe carefully
耳を澄ます[mimiwosumasu] to listen carefully
上澄[uwazumi] the clear top of a liquid
澄まし屋[sumashiya] a prim person
澄まし顔[sumashigao] composed expression

澄ます[sumasu] to clear
澄みきる[sumikiru] to be serene
澄み渡る[sumiwataru] to be perfectly clear
澄む[sumu] to clear (e.g. weather)
清澄[seichou] clear