What is Annus Luctus?

Legal Definition
The year of mourning. It was a rule among the Romans, and also the Danes and Saxons, that widows should not marry infra annum luctds, (within the year of mourning.) Code 5, 9, 2; 1 Bl. Comm. 457.
-- Black's Law Dictionary
Legal Definition
The year of mourning immediately succeeding a husband’s death and during which his widow could not remarry. See 1 Bl. Comm. 456.
-- Ballentine's Law Dictionary