An expression of onomonopeai just like Bang or Kaboom. You say fwoomph when something large hits the ground or when something critical to the mission is achieved while stoned.
Stoner 1: Dude, did you see that dude fall when he uhh fell?
Stoner 2: Ya, he hit the ground like fwoomph!
Stoner 2: Ya, he hit the ground like fwoomph!
by Mike April 25, 2005