sec·ond na·ture
noun/ˌsekənd ˈneɪtʃə(r)/
/ˌsekənd ˈneɪtʃər/
[uncountable]- second nature (to somebody) (to do something) something that you do very easily and naturally, because it is part of your character or you have done it so many times
第二天性；习性 - He found that teaching was second nature to him.
他发现教学是他的第二天性。
- He found that teaching was second nature to him.