Search Result for "sister-in-law": 
Wordnet 3.0

NOUN (1)

1. the sister of your spouse; 



The Collaborative International Dictionary of English v.0.48:

Sister-in-law \Sis"ter-in-law`\, n.; pl. Sisters-in-law.
   The sister of one's husband or wife; also, the wife of one's
   brother; sometimes, the wife of one's husband's or wife's
   brother.
   [1913 Webster]


WordNet (r) 3.0 (2006):

sister-in-law
    n 1: the sister of your spouse