When you are smoking the last bit of pot in a pipe, and one of the hot ashes shoots through the bowl and hits the back of your throat. Can usually be seen as a bright orange ball flying through the length of the pipe if it is made of glass.
*coughing* Dammit! That pot comet just burnt the shit out of my throat...
by Mike Coff May 03, 2006
its when you are getting your pot out of it's medium of transportation, and the shake flys all over the place..
"Hey man ill pack a bowl, here let me get my pot... oh shit, pot comet!"
by Officer O'Reily May 08, 2005