か弱い[kayowai] frail
ひ弱い[hiyowai] weak
意志薄弱[ishihakujaku] weak-willed
胃弱[ijaku] dyspepsia
虚弱[kyojaku] feebleness

強弱[kyoujaku] strength
弱い[yowai] weak
弱い者[yowaimono] weak person
弱い相互作用[yowaisougosayou] weak interaction (physics)

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