まっ四角[masshikaku] square
一天四海[ittenshikai] the world
下四半期[shimoshihanki] last quarter (of the year)
弦楽四重奏曲[gengakushijuusoukyoku] string quartet
再三再四[saisansaishi] repeatedly

三寒四温[sankanshion] alternation of three cold and four warm days
四つ[yottsu] four
四つんばい[yotsunbai] (crawl) on all fours
四つ角[yotsukado] four corners
四つ足[yotsuashi] four-footed (animal)

雨子[amago] land-locked variety of red-spotted masu trout (Oncorhynchus masou ishikawae)
御菓子[okashi] confections
お子さん[okosan] (someone else's) child
お子様[okosama] child (someone else's)
山梔子[kuchinashi] Cape jasmine (Gardenia jasminoides)

させ子[saseko] whore
梃子摺る[tekozuru] to have much trouble
螺子回し[nejimawashi] screwdriver
硝子[garasu] glass
獅子女[sufinkusu] sphinx

拍手を打つ[kashiwadewoutsu] to clap one's hands in prayer
口拍子[kuchibyoushi] counting time orally
三拍子[sanbyoushi] triple time (music)
手拍子[tebyoushi] beating time
心拍[shinpaku] heart rate

二拍子[nibyoushi] duple meter
拍子木[hyoushigi] wooden clappers
拍車[hakusha] (riding) spur
拍車をかける[hakushawokakeru] to spur (on)
拍手[hakushu] clapping hands