Stupidity in a woman is unfeminine.
I'm feminine: I'm wearing a skirt, I own a bra. I think that whole big blonde look has been taken over by transsexuals now. I'm a natural blonde, but that blonde hair, big tits idea of what men want, it's now really unfeminine.
Not many women will go out on a limb to make themselves really unattractive and unfeminine so you can get the laughs, but it's a great thing to do in my book.
One distressing thing is the way men react to women who assert their equality: their ultimate weapon is to call them unfeminine. They think she is anti-male; they even whisper that she's probably a lesbian.