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

枯淡[kotan] elegant simplicity
淡い[awai] light
淡黄色[tanoushoku] pale yellow
淡紅色[tankoushoku] pink
淡彩[tansai] light colouring

淡水[tansui] fresh water (i.e. not salt water)
淡雪[awayuki] light snowfall
濃淡[noutan] light and shade
濃淡画像[noutangazou] gray-scale image
平淡[heitan] simple

天魚[amago] land-locked variety of red-spotted masu trout (Oncorhynchus masou ishikawae)
海鷂魚[ei] ray (fish)
斉魚[etsu] Japanese grenadier anchovy (Coilia nasus)
旗魚[kajiki] marlin
鶏魚[isagi] chicken grunt (species of fish, Parapristipoma trilineatum)

杜父魚[tofugyo] sculpin (any fish of family Cottidae, inc. the bullheads and the miller's-thumb)
堅魚[katsuo] skipjack tuna
魚網[gyomou] fishing net
魚屋[sakanaya] fish market
魚貝[gyokai] marine products