这楼层已定为无烟区。

This floor has been designated a no-smoking area.

《牛津词典》

本区已定为国家公园。

This area has been designated (as) a National Park.

《牛津词典》

我听说，我被定为提升的人选。

I was told that I was being slated for promotion.

《牛津词典》

So, for example, if we're to hold the time constant, this makes it a lot simpler of an equation, because what we can end up doing is actually crossing out this whole term here.

比如说，如果我们把时间,定为常数，这使得方程,大大简化，因为我们可以把,这一项划掉。

麻省理工公开课 - 化学原理课程节选

They said five years is too short--it's got to be longer -they said fifteen years.

他们说五年太短,要长一点,应该定为十五年

耶鲁公开课 - 金融市场课程节选

You can call that your origin.

你也可以把这里定为原点

耶鲁公开课 - 基础物理课程节选