A buff is someone who has a strong, special interest in something.

VOA: special.2009.05.17

Temporarily, as we advance through the syllabus, we're bracketing or suspending our interest in meaning and focusing instead on how something is made.

但是根据课程大纲，我们要暂时收起对于文本含义的兴趣,转而探索文本是怎么组合的。

耶鲁公开课 - 文学理论导论课程节选

I lose my interest in philosophy and take up an interest in, I don't know,something that completely doesn't-- organic chemistry holds no interest to me whatsoever.

我失去了对哲学的兴趣，对一个完全不相干的东西-,比如以前完全不感兴趣的有机化学。

耶鲁公开课 - 死亡课程节选

The interest in wealthy people may have something to do with the increasing difference between the richest and poorest Americans.

VOA: special.2010.11.22

And there's every indication that -- and I mentioned before, of course -- there's every indication that a lot of these early works bespeak something like a serious interest in the ideal of a lifelong state of chastity.

有各种各样的暗示--当然我之前也提到过，有各种各样的暗示表明大部分早期作品,都显现出一种重要的兴趣,有关于保持终生贞洁的观点。

耶鲁公开课 - 弥尔顿课程节选