Grumpin' 

(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...

Grumpin' by SneakyMe August 29, 2011

grumpin

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)

grumpin by Bryan Harving November 4, 2007

Grumpin

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 -

Grumpin by KSWingNut January 16, 2011

Grumpin

(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...

Grumpin by SneakyMe September 2, 2011

Grumpin

A slang for someone who has a massive pp

“Wow he’s grumpin”

Grumpin by TheImpish March 7, 2021

It's Grumpin' Time 

When it is time to Grump.

Epic Grumpyre: It's Grumpin' Time!

Matt: Oh no

It's Grumpin' Time by msmfart July 28, 2022

It's Grumpin Time 

The Catchphrase of Epic Grumpyre from My Singing Monsters.

"The Shadow Elemental can hear even the most hushed lip-smacking of any Monster enjoying Treats, and particularly loves to mutter the catchphrase, "It's Grumpin time," as it enjoys a late night snack of its own."

It's Grumpin Time by Jack the Weirdo Thing August 14, 2022