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