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)

四つん這い[yottsunbai] (crawl) on all fours
出這入り[dehairi] in and out
這入り込む[irikomu] to go into
這入る[hairu] to enter
這い松[haimatsu] creeping pine

這い這い[haihai] creeping
這う[hau] to creep
腹這い[harabai] lying on one's belly
夜這い[yobai] creeping at night into a woman's bedroom
這い回る[haimawaru] to creep about