libber
A female activist who advocates strongly for the rights, liberty, and equality of women. Shortened from "women's libber," itself a shortening of "women's liberation (movement)" with the suffix "-er" to indicate agency. Sometimes used as an insulting or derogatory term. I wouldn't necessarily consider myself a libber, but I am definitely in support of feminism. That just sounds like something a man-hating libber would say.
libber
(ˈlɪbɚ) n. a woman who advocates woman’s liberation movements; a feminist. (Usually derogatory.) She sure sounds like a libber.