The word duchess does not have an opposite. There are some serious misunderstandings about the meaning of the word opposite. A duke is a counterpart of duchess; it is not opposite.
Win
duchess
Duke.
A duke a male, a duchess is a female.
Duchess.
A duchess is the highest ranking non-royal inherited peerage title. Its male counterpart is a duke.
duchess
The opposite of a duchess would be a duke
The opposite of a duchess would be a duke. The British used these terms to refer to the noblemen and women.
Duke
Duke.
A duke a male, a duchess is a female.
The opposite of Duke was Duchess. Duke and Duchess were titles of nobility in England. Duke is also the highest ranking hereditary title of the four titles in England.
duchess (the female, not so much opposite)
The title for a male is duke; the title for a female (opposite by gender) is duchess.duchess
The duchess in The Duchess and the Jeweler were greedy. This was a short story written by Virginia Woolf.
Duchess.
Female verism title for Duke is Duchess