unbend

动词 unbend:

1. straighten up or out; make straight
   同义词：straighten
2. unfasten, as a sail, from a spar or a stay
3. free from flexure
4. make less tight
   同义词：relax
5. become less tense, rest, or take one's ease
   同义词：relax, loosen up, unwind, decompress, slow down
6. release from mental strain, tension, or formality

1. She was very formal at first, but then she unbent a little and told a joke.
   她起先显得很正经，但后来变得随和些，还讲了个笑话。
2. Most professors unbend outside the lecture theatre.
   教授在课下大都很随便。