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

火災[kasai] conflagration
火災保険[kasaihoken] fire insurance
核災害[kakusaigai] nuclear disaster
公務災害[koumusaigai] accidents in line of duty
災い[wazawai] calamity

災禍[saika] accident
災害[saigai] calamity
災難[sainan] calamity
災難に遭う[sainanniau] to meet with misfortune
災厄[saiyaku] calamity