どら息子[doramusuko] lazy son
愛息[aisoku] (your) beloved son
安息[ansoku] rest
一人息子[hitorimusuko] an only son
一息[hitoiki] one breath

因循姑息[injunkosoku] dilly-dallying and temporizing (temporising)
気息[kisoku] breathing
気息奄奄[kisokuenen] gasping for breath
休息[kyuusoku] rest
休息時間[kyuusokujikan] recess

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