to believe something to be true because it is very likely, although you are not certain

[ + (that) ] I presume (that) they're not coming, since they haven't replied to the invitation. 鉴于他们没有回复邀请，我认为他们不会来了。

[ + speech ] You are Dr Smith, I presume? 我想你是史密斯博士吧？

"Are we walking to the hotel?" "I presume not/so." “我们走着去旅馆吗？”“我想不是／是的。”

[ + obj + adj ] The boat's captain is missing, presumed dead (= it is believed that he is dead). 这条船的船长失踪了，估计是死了。

In British law, you are presumed innocent until you are proved guilty. 按英国法律，在证明你有罪前，假定你是无辜的。

[ + obj + to infinitive ] The universe is presumed to contain many other planets with some form of life. 据推测，宇宙中很多其他的行星上有某种形式的生命存在。

to do something although you know that you do not have a right to do it

[ + to infinitive ] I wouldn't presume to tell you how to do your job, but shouldn't this piece go there? 我不想冒昧地教你该如何工作，但这个零件不是应该装在那里吗？

I don't wish to presume (= make a suggestion although I have no right to), but don't you think you should apologize to her? 恕我冒昧，但你难道不觉得应该向她道歉吗？

He presumes on her good nature (= takes unfair advantage of it). 他利用了她的善良本性。