num. 第一千 (The thousandth item in a series is the one that you count as number one thousand.)

A micrometer is one thousandth of one millimeter.

一微米是一毫米的千分之一。

For the thousandth time, he wrote down her name in the notebook.

他在笔记本上写下她的名字，这已是第一千遍了。

She said goodbye to him for the thousandth time.

她第一千次和她告别。

相关单词

基数词：one thousand

缩写词：1000th