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

河内[hanoi] Hanoi
運河[unga] canal
応急渡河[oukyuutoka] hasty crossing
黄河[kouga] Yellow river (in China)
河港[kakou] river port

河鹿[kajika] kajika frog (Buergeria buergeri)
河床[kashou] riverbed
河水[kasui] river water
河川[kasen] rivers
河童[kappa] kappa (mythical water-dwelling creatures)