adj.第一千
n.千分之一
He repeated the sentence for the thousandth time. 他把那句话重复了无数遍。
The city will celebrate its thousandth anniversary tomorrow. 这座城市明天将庆祝建城一千周年。
A dust particle weighs only a thousandth of a gram. 一粒尘埃的重量仅有千分之一克。
