Mumbly Grumbly 

Term used to describe someone who complains, bitches and moans all the time but does it in a low 'mumbled' voice, and in low, run-on sentences so you can't understand what they are saying.
Usually, but not always, limited to grumpy old men.

That old dude looks mad, and keeps mumbling something, but I can't understand him.
Yeah that's old man Withers...he's always all Mumbly Grumbly.

Mumbly Grumbly by phoenixxx70 May 14, 2010

Grumblebrag 

To complain in a superficial manner, when one is really just boasting.

I have to wear my wedding ring or else I just get hit on too much. I'm not actually annoyed, I'm just grumblebragging.

Grumblebrag by das Luftkissenboot November 13, 2014

grundle grumble 

grundle grumble ( grundle grumbler, grundle grumbling )

1: When a young lady is pleasuring her partner by kissing or licking his grundle the scrotum will cover the womans mouth preventing intelligible speech.

2: Flatulence that is prevented from escaping up the butt crack that flows over the grundle impacting the scrotum making a distinctive rumbling sound. Grundle grumbles are particularly evident when seated on leather or vinyl seating surfaces or those cheesy fiberglass chairs in laundromats.

3. Mysterious sounds that emanate from the grundle.

1. Whats that honey? I can't hear what you saying you grundle grumbling bitch you.

2. Jesus Dave I heard that grundle grumble from here. Stop farting on my leather seats..no more fucking burritos for you.

3. What the fuck was that? Oh..a fucking grundle grumble. Sorry. Do you have any fabric softener?

grundle grumble by Global Feetus April 2, 2007

grumblump

A level name in the final world of Super Mario 3D World

Don't look up Grumblump on Urban Dictionary. - RedFalcon, 2021

grumblump by 5003erX March 5, 2021

gumblybub 

A toy to entertain children, often located in places of business, car showrooms or airports. It consists of a dedicated table with numerous individual wire shapes attached to the surface. These wire shapes include rainbow, loop-the-loop and corkscrew. Beads with holes through the middle are attached to the wires, and the child pushes the beads back and forth through them.

Darling, where's Timmy?
He's playing with the gumblybub, I'll go and get him.

gumblybub by lardless March 13, 2005

Grimbly 

According to Ted Nivison of the Chuckle Sandwich podcast, a grimbly is a tupper that specifically goes in wares.

Dude, I think a grimbly just climed up my pant leg

Grimbly by saltmydishbartender May 20, 2022

Grimbly 

Just a little green guy. They thirst for blood and when given thickening powder from Walgreens they devour it and start to chulk

The grimblys bit holes into his skin, trying to burrow and drink the blood.

Grimbly by Nibble101 May 25, 2022