to reduce something, such as a speech or piece of writing, in length

I condensed ten pages of comments into/to two. 我将十页的评论压缩成了两页。

to make a liquid thicker by removing some of the water

to change or make something change from a gas to a liquid or solid state

Water vapour in the air condenses into fog. 空气中的水汽凝结形成雾。