御三時[osanji] three-o'clock snack
三鞭酒[shanpen] champagne
球面三角法[kyuumensankakuhou] spherical trigonometry
胸三寸[munesanzun] heart
元三[ganzan] New Year's period (January 1st to 3rd)

五十三次[gojuusantsugi] the 53 Toukaidou stages
向こう三軒[mukousangen] one's next three neighbors
降三世明王[gouzanzemyouou] Trailokyavijaya Vidya-raja
再三[saisan] again and again
再三再四[saisansaishi] repeatedly

庵室[anshitsu] hermit's cell
暗室[anshitsu] dark room
医務室[imushitsu] doctor's office
育児室[ikujishitsu] nursery
一室[isshitsu] one room

閲覧室[etsuranshitsu] inspection room
応接室[ousetsushitsu] drawing room
王室[oushitsu] royal family
温室[onshitsu] greenhouse
化粧室[keshoushitsu] toilet

ゴミ集積場[gomishuusekijou] village garbage collection point
欝積[usseki] accumulation (e.g. of emotions, grievances, etc.)
沖積[chuuseki] alluvial
沖積期[chuusekiki] alluvial period
沖積世[chuusekisei] alluvial epoch (i.e. the Holocene epoch)

沖積層[chuusekisou] alluvium
沖積土[chuusekido] alluvial soil
下積み[shitazumi] lowest social strata
求積[kyuuseki] mensuration
経路積分[keirosekibun] path integral (physics)