grumperoo 

someone who is really grumpy

Tony stop acting like such a big grumperoo, im sorry you dont have your homo milk for your coffee

grumperoo by are ess see December 18, 2008

Grumper 

An especially hot and steamy shit. Grumpers often leave you very sweaty and exhausted. They're mostly taken under less than ideal situations like port-o-johns and bar bathrooms.

Man I was tailgating on Saturday and I had to shit some fierce. I went to the port-o-John and dropped a fiery grumper. My asshole was never the same.

Grumper by Alexdlegit March 25, 2017

Grumperson Jones 

An extremely grumpy, cranky, or unhappy individual.

Watch out, Greg is a Grumperson Jones today!

Grumperson Jones by Emily Jones-Parker July 28, 2010

Niagara Grumper 

An explosive shit. Comes pouring out of your ass with seemingly no end to the flow. Like a hot waterfall of shit.

I ate some bad oysters last night and today I experienced the worst Niagara Grumper. I couldn’t get off the shitter.

Niagara Grumper by Eaton Holgoode January 25, 2018

Grumper 

A very humorous word for poop.

Damn it, I just stepped in the biggest pile of grumper!

Grumper by benwad934 March 30, 2004

grumper 

A defecation that requires mass force to expel.

Oh man, I can tell this one is going to be a real grumper.

grumper by John Clever November 27, 2002

Grumper 

A new social networking site that is growing in popularity. Where the Internet goes to complain. www.grumper.org

I posted a grump about swine flu on Grumper. You should check it out and grump it.

Grumper by Asyra June 10, 2009