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

栖息[seisoku] inhabiting
隠栖[insei] secluded life
旧栖[kyuusei] old home
幽栖[yuusei] living a quiet life in seclusion away from the masses

栖む[sumu] to live (of animals)
羊栖菜[hijiki] hijiki (dark edible seaweed usu. sold in dried black strips; Hizikia fusiformis)
終の栖[tsuinosumika] one's final abode

共棲[tomoiki] symbiosis
棲家[sumika] dwelling
水棲[suisei] aquatic (life)
棲息[seisoku] inhabiting
同棲[dousei] cohabitation

両棲[ryousei] amphibious
隠棲[insei] secluded life
旧棲[kyuusei] old home
棲み分け[sumiwake] habitat isolation (biology)
両棲動物[ryouseidoubutsu] amphibious animal

お生憎様[oainikusama] that's too bad (ironical)
御誕生日おめでとうございます[otanjoubiomedetougozaimasu] Happy Birthday
隣の芝生は青い[tonarinoshibafuhaaoi] the grass is always greener on the other side
生きがいい[ikigaii] fresh (e.g. fish)
コンピューター援用生産[konpyuutaaenyouseisan] computer-aided manufacture

委託生[itakusei] scholarship student sent by government office or business
生す[nasu] to build up
異常発生[ijouhassei] plague
医学生[igakusei] medical student
医学生物学[igakuseibutsugaku] medical biology