thirtiethKK [ˋθɝtiəθ] /ˈθɝtiəθ/形容詞1第三十、第三十個She is celebrating her thirtieth year with the company.她正在慶祝進入公司的第三十年。2三十分之一的He finished just a thirtieth of a second behind the winner.他只以三十分之一秒之差落後冠軍。名詞1三十日、三十號多與 the 連用The meeting has been moved to the thirtieth of next month.會議已改到下個月三十號。2第三十個多與 the 連用This is the thirtieth in a long series of delays.這是一連串延誤中的第三十次。3三十分之一Each investor owns a thirtieth of the building.每位投資人各擁有這棟建築的三十分之一。