Someone who is unusually fat and short at the same time. It does not have anything to do with a dumpster or being dirty. It is very similar to a chode, a penis that is fatter than it is long. Many girls can be called dumpy even if they are just a little bit squat.
Example: "I don't know what you were thinkin last night dude, that flooz was dumpy as hell. Were you blind - she was like 5'1" with a gut. She was pretty much Yoda."
Example: Steve (Person 1): Hey, you see that chick over there?
Jay (Person 2): Yeah. Why?
Steve (Person 1): She got a dumpy, doesn't she?
Jay (Person 2): Yeah, she does.
Steve (Person 1): Let's go over there and slap that luxurious thing.
Jay (Person 2): Roger that.