people under the influence of muzz are likely to trip, break things or generally fuck up the simplest of tasks
"dude, i am so muzzed"
"I'm just muzzing out"
*in exsaperated tone* "Muuuuuuuuuuzzzzzzzzzzz"
"Ramwell, stop muzzing out -- you left my house unlocked and two bongs on my parents kitchen table"
A more direct method of referring to a fun sponge; someone who sucks the enjoyment out of any situation. Can also refer to the sucking sound of people's enjoyment leaving them.
"Damn that muzz Jeff; everytime he comes over no-one wants to stay."