1) A portmanteau of the words vegetarian and poser. This term commonly is associated with a person who becomes a vegetarian for superficial or foolish reasons, rather than understanding the true meaning of vegetarianism. Can also be spelled vegetariposeur.
2) A derogatory term for a vegetarian.
Vegetariposer: Oh my gosh, I can now fit into a size zero and, like, become popular by being a vegetarian! And I'm soo straight-edge! I'm totally getting a date to the prom with the popular boy!
Real Vegetarian: Shut up, vegetariposer. You don't understand the true meaning of vegetarianism, do you?
Bully: Wow, you're such a vegetariposer with your tofu garbage! Tofu smells like fart and it makes you ugly! No wonder you don't have a girlfriend!
Vegetarian: At least I'm not the one who'll be getting mad cow disease and being a fatty from all that McDonald's crap.