どん底[donzoko] very bottom
井底[seitei] well bottom
海底[kaitei] bottom of the ocean
海底ケーブル[kaiteikeeburu] undersea cable
丸底[maruzoko] round-bottom

基底[kitei] base
靴底[kutsuzoko] shoe sole
黒底翳[kurosokohi] black cataract
根底[kontei] root
周知徹底[shuuchitettei] (something) known to all

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