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)

俗諦[zokutai] simplified teaching
諦め[akirame] resignation
諦める[akirameru] to give up
諦観[teikan] clear vision
真諦[shintai] ultimate truth

要諦[youtei] important point
諦念[teinen] a heart that understands truth
四諦[shitai] The Four Noble Truths (of Buddhism)
諦めが付く[akiramegatsuku] to give up
諦めつく[akirametsuku] to give up