Dictionary
sis•ter-in-law
Pronunciation: (sis'tur-in-lô"), [key]—
n.,
—pl. sis•ters-in-law.
1. the sister of one's husband or wife.
2. the wife of one's brother.
3. the wife of the brother of one's husband or wife.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.