Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
brother-in-law [ˈbrʌðərɪnlɔː] n (sister's husband) зять*m (wife's brother) шу́рин#; (husband's brother) де́верь*m
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: