n.[C]

1. 码尺（一码长的尺）
2. 衡量标准，评价标准[（+of/for/against）]
   Do you think the TOEFL score is a good yardstick for English proficiency?

   你认为托福成绩是一种衡量英语流利程度的好标准吗？

   She was a yardstick against which I could measure my achievements.

   她是我可以用来衡量我的成就的准绳。

n.

1. a measuring rod a yard long.
2. a standard used for comparison.