A virago is a woman who demonstrates abundant masculine virtues. The word comes from the Latin word virāgō (genitive virāginis) meaning vigorous' from vir meaning "man" or "man-like" (cf. virile and virtue) to which the suffix -āgō is added, a suffix that creates a new noun of the third declension with feminine grammatical gender. Historically, this was often positive and reflected heroism and exemplary qualities of masculinity. However, it could also be pejorative, indicating a woman who is masculine to the exclusion of traditional feminine virtues.

Modern use of the word virago generally takes the disparaging sense. Thus virago joined pejoratives such as termagant, mannish, amazonian and shrew to describe women who acted aggressively or like men. The word virago has almost always had an association with cultural gender transgression. There are recorded instances of viragos (such as Joan of Arc) fighting battles, wearing men's clothing, or receiving the tonsure.