Vidua Regis
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
Lat.
In old English law
A king's widow
The widow of a tenant in capite. So called, because she was not allowed to marry a second time without the king's permission; obtaining her dower also from the assignment of the king, and having the king for her patron and defender.
Spelman.