levirate

adj

1. (not-comparable)Having to do with one's husband's brother.

noun

1. (countable)A marriage between a widow and her deceased husband's brother or, sometimes, heir.
2. The institution of levirate marriage.

   “And it is, he says, impossible not to believe that the Levirate—that is, the practice of marrying a dead brother's widow—is derived from polyandry.”

   “It is only a secondary purpose of the levirate that the property of the deceased passes on to the one who is heir to his name, and is probably a later accretion.”

   “The levirate is found in patrilineal societies in which the bride marries into her husband's family while essentially severing her ties with her original family.”