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)

慰霊祭[ireisai] memorial service
英霊[eirei] spirits of war dead
怨霊[onryou] revengeful ghost
こと霊[kotodama] soul of language
降霊術[koureijutsu] necromancy

合同慰霊祭[goudouireisai] joint service for the war dead
黒人霊歌[kokujinreika] Negro spiritual
死霊[shiryou] spirit of a dead person
除霊[jorei] exorcism
心霊[shinrei] spirit (e.g. human spirit)