look up any word, like tribbing:
 
2.
(verb) The act of vigorously passing a particularly stubborn bowel movement. Usually involves grunting and the straining of one's sphincter. See also: Constipation
I hate when I'm in the bathroom at work and someone is grumpin' out a gnarly deuce. Gross...
by SneakyMe August 31, 2011
 
1.
(verb) The act of vigorously passing a particularly stubborn bowel movement. Usually involves grunting and the straining of one's sphincter. See also: Constipation
I hate when I'm in the bathroom at work and someone is grumpin' out a gnarly deuce. Gross...
by SneakyMe August 26, 2011
 
3.
grumpin is the slang term for actively making yourself grumpy(to the extreme)
grumpin comes about while talking to Asians about big trucks, and fast cars (besides Toyota MR-2's)
by Bryan Harving October 18, 2007
 
4.
A person in the act of or a participant of farting in bath tub. pool or body of water and catching tainted bubbles in mouth.
A person sets in bath tub lets one loose and bends down to catch fart bubbles in mouth. - Grumpin -
by KSWingNut January 15, 2011