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1.
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.
by phoenixxx70 May 14, 2010

Words related to Mumbly Grumbly

ebonics fail fail at life fyl noob ridiculous smh stupid