一億[ichioku] 100,000,000
億ション[okushon] (luxury) apartment
億円[okuen] 100,000,000 yen
億劫[okkuu] troublesome
億兆[okuchou] the people

億万長者[okumanchouja] billionaire
十億[juuoku] 1,000,000,000
十万億土[juumanokudo] eternity
数億年[suuokunen] several hundred million years

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