ˈbrother-in-law BrE AmE noun ( plural brothers-in-law ) [countable]
1 . the brother of your husband or wife
2 . the husband of your sister
3 . the husband of your husband or wife’s sister
⇨ sister-in-law
ˈbrother-in-law BrE AmE noun ( plural brothers-in-law ) [countable]
1 . the brother of your husband or wife
2 . the husband of your sister
3 . the husband of your husband or wife’s sister
⇨ sister-in-law
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012