永劫[eigou] eternity
億劫[okkuu] troublesome
劫火[gouka] world-destroying conflagration
劫盗[goutou] highway robber
劫罰[goubatsu] eternal punishment

劫かす[obiyakasu] to intimidate
劫略[gouryaku] pillage
万劫[bangou] eternity
未来永劫[miraieigou] eternity

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)