noun
A person who supports feminism; used for both men and women. The primary modern meaning.
彼女は熱心なフェミニストで、男女平等を強く主張している。
She is a passionate feminist and strongly advocates for gender equality.
noun
man who is attentive to women; gentleman
A somewhat dated or colloquial use, describing a man who treats women with special kindness or chivalry, sometimes with a nuance of indulgence. Not the primary meaning.
彼はいつも女性にドアを開けてあげる、ちょっとしたフェミニストだ。
He always opens doors for women; he's a bit of a gentleman.