dowager

Definitions:

A widow with a jointure; the widow particularly of a prince or a noble.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
The widow of a king, prince, or person of rank; a widow who has inherited property.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
A title given to the widow of a prince or person of rank when he who succeeded her deceased husband in his titles and estates is married, there being thus two ladies with the same title; a widow of rank, with property or real estate enjoyed by her during her lifetime.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
A widow with a dower or jointure: a title given to a widow to distinguish her from the wife of her husband's heir.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
A widow with a dower.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)

Usage examples:

Upon my word, mamma, she exclaims, you are a singularly fortunate dowager
- Floyd Grandon's Honor by Amanda Minnie Douglas
So the Dowager Duchess melted out of the story, and Lady Bridget- Mary Bawne became a nun.
- The Dop Doctor by Clotilde Inez Mary Graves
Well- But the poor baby, how could he expect to see through a game that had caught the Dowager herself?
- In the Bishop's Carriage by Miriam Michelson