brother-in-law
n. 内兄,内弟; 大伯,小叔; 姐夫,妹夫; 连襟
Someone's brother-in-law is the brother of their husband or wife, or the man who is married to their sister.
1. a brother by marriage
brothers-in-law
relative
n. 姊夫,妹夫;连襟;内兄
sister-in-law