1) Institution 
custom of compulsory marriage with brother's widow
• (a.) Alt. of Leviratical
custom or law decreeing a dead man`s brother to be the preferred, and in rare cases the mandatory, marriage partner of the widow. The term comes ... [7 related articles]
Form of marriage in which a man is required to marry the widow of a brother who dies without a male heir. Children of the marriage are legally those of the dead brother. The purpose is to provide...
Lev'i·rate (lĕv'ĭ*rat), Lev`i*rat'ic*al (-răt'ĭ*k a l) adjective [ Latin levir a husband's brother, brother- in-law; akin to Greek 
levirate 1. Brother-in-law. 2. The custom among the Jews and some other nations, by which the brother or next of kin to a deceased man was bound under certain circumstances to marry the widow.
noun the biblical institution whereby a man must marry the widow of his childless brother in order to maintain the brother`s line