Bastardization of vegetarian used for dry humor. The idea is that the user has never heard of vegetarianism and thinks he is inventing the
word for it when somebody says that they don't eat
meat.
The humor comes from oversimplification, implied ignorance, and laughable wordcoinning. It also kinda sounds
like Unitarian, implying a quasi-religious respect for vegetables.
Dude: Have some chicken fingers.
Loser: I don't eat
meat
Dude: Chicken is barely
meat.
Loser: I NEVER eat meat, I'm a vegetarian
Dude: Oh, so you're
like a vegetableitarian?
Loser: ehhh...I guess.
Dude: Sorry, I didn't mean for you to go against your "religion"
Loser: (huhhh?)