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

蝦夷[ezo] peoples formerly of northern Japan with distinct language and culture (i.e. the Ainu)
青竜蝦[shako] mantis shrimp (any marine crustacean of order Stomatopoda, esp. the species Oratosquilla oratoria)
車蝦[kurumaebi] kuruma prawn (Marsupenaeus japonicus)
蝦蟆[hikigaeru] toad (esp. the Japanese toad, Bufo japonicus)
蝦虎魚[haze] goby (fish)

竜蝦[iseebi] spiny lobster (esp. Japanese spiny lobster, Panulirus japonicus)
蝦夷松[ezomatsu] Yezo spruce (Picea jezoensis)
蝦夷菊[ezogiku] Chinese aster
蝦腰[ebigoshi] bent (with age)

醤油[shouyu] soy sauce
生醤油[kijouyu] pure soy sauce
醤蝦[ami] opossum shrimp (Mysida spp.)
沖醤蝦[okiami] krill
醤油顔[shouyugao] someone with a slender chin

豆瓣醤[toobanjan] broad bean chili paste (Chinese seasoning)
ポン酢醤油[ponzushouyu] ponzu (Japanese sauce made primarily of soy sauce and citrus juice)
魚醤[gyoshou] fish sauce (made from fermented salted fish)
魚醤油[uoshouyu] fish sauce (made from fermented salted fish)
たまり醤油[tamarijouyu] tamari soy sauce