I'm happy with the "seeks equality between men and women" definition; all the people who hold that view would presumably be masculinists if the shoe were on the other foot.

I'm also happy with it as a descriptive term, not (just) a defining one; if I say "feminist" I mean everyone who holds that view, not just those who hold that view and call themselves that.

Of the people who think "feminist" means something else, I'm hard put to think of significantly many people who call themselves feminists but have some other definition, yet you can barely utter the word without someone popping up who denies they're a feminist because they think it means something else, yet also holds the view I call feminism.

(Of course, maybe this last is just a fact about my experience, rather than about the world.)