1. Usually to strongly agree with what one is saying.
2. To affirm something.
3.Substitution for "yep", "yes",
"yeah", etc.
1. -"Damn those are some big ass tits"
-"YUMP!" (strong usage)
2. -"Check out that ass"
-"Yump" (medium)
3. -"What a bitch"
-"yump" (mild, to simply agree)
By Mattie
Yump
A small jump often formed by a crest in a road or path of a rally racing special-stage. The term "yump" is believed to have originated from foreign drivers' pronunciation of "jump".