A term guys use to guilt girls into going out with them out of pity.
John: Stacey, will you go out with me?
Stacey: I'm sorry, John, but no.
John: *later to friends* And then she totally friend zoned me, dude! So unfair, I've spent too much time with her doing amazing things for her to not be riding that shit! I'm entitled to bang her, now, but she's being a bitch!
Friend: Dude she didn't friend zone you you're just a douchebag.