The act of taking an enormous dump on any type of floor. The act is usually performed when one is scared shitless and one is not able to reach a shower to take a shump.
Nessie took a flump when she failed her English exam qand could not find a shower to shump. She immediately proceeded to take of her pants, sit on the floor, and take a nice, long, warm flump.
The act of collapsing onto something or someone like a sad, jiggly, shoved over serving of jello.
Person #1: I'm gonna flump on you now.
Person #2: Oh god no...
Person #1: *getting closer* I'm gonna do it
Person #2 doN'T YOU FUCKING DA-
Person #1: *flumps onto person #2) I did it.
Person #2 *flailing like an aggressive kitten* GOD FUCKING DAMNIT!!