from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The custom of marriage of a man to his wife's sister or sisters, usually after the wife has died or proved sterile.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The custom of the marriage of a man to the sister of his wife, usually after the wife has died.
- n. A marriage according to this custom.
From Latin soror, sister; see sororal.(American Heritage® Dictionary of the English Language, Fourth Edition)
Latin soror ("sister"). (Wiktionary)