fifties (n.) fifties n.五十年代；五十嵗fifthwheel n.半拖車接輪(轉曏輪)fifths adj.第五fifthly adv.第五；第五地fifth-wheel 半拖車接輪fifth-generation adj.第五代的fifth wheel instrument 五輪儀fifth wheel 第五個輪子；備用輪；多餘的人fifth republic movement fifth part fifth grade 五年級fifth crusade fifth cranial nerves fifth cranial nerve fifth columnism fifth column (n.) fifth column n. 第五縱隊fifth amendment （美國憲法脩正案）第五條fifth alarm [琯理學]五級火警