Someone who will readily smoke your weed without matching with some of his.
A person who will get cut in on a joint or a bowl and suck half the thing down or double/triple hoot.
I don't want Bill to come along this time, he's such a gomer.
Student 2:Nah, but I'm sure Bob will play, he's INSANE at Starcraft.
Student 1:Who's Bob?
Student 2:Oh, you've probably never seen him, he's a gomer.