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)

胡麻化し[gomakashi] hanky-panky
荏胡麻[egoma] egoma (type of perilla)
荏胡麻油[egomayu] egoma seed oil
胡獱[todo] Steller's sea lion
胡国[kokoku] North China barbarian nations

胡床[agura] sitting cross-legged (i.e. Indian style)
胡床をかく[agurawokaku] to sit cross-legged
胡散臭い[usankusai] suspicious looking
胡桃[kurumi] walnut
胡麻[goma] sesame (seeds)