A knob in a state of high alert, viz a viz a watchdog or robber's cur. A slightly less prepared version is know as a half-mongrel, or slung-mong.
Oaf: "By crikey, I'm so enamoured of that gentlelady that my mongrel is verily frothing at the mouth. I fear I shall soil my tweeds with nut muck!"
by Mr Marky January 30, 2008
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Someone who parties exessively hard at all times.
Dude, it's Mongrel Monday. Come down to the house and pound this keg-dog.

Dude, I was such a mongrel last night when I pounded all those brews/shots.
by Mongrelface McG April 22, 2010
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Used to describe someone who's accent is all over the place. Intended as a compliment.

Definitely not racist.
That girl sounded like she was from Manchester, Wales and Lincoln all at the same time - she was a proper mongrel-in a good way
by Granny robber July 15, 2015
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Anyone called Max, especially the basketball players
Ah you're such a mongrel Max!!
by Daniel998799871 June 24, 2018
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American Mongrel (or Mutt) is a derogatory word to describe the Americans, for being part of a Melting Pot, where everyone is mixed with one another.
"America is a mongrel nation run by Jews"
- Adolf Hitler

"We are sort of a mongrel people"
- Barack Obama

Example:
John: Hey look! There goes that American mongrel.
Peter: These American tourists are everywhere in Europe now.
John: Tell me about it. Bunch of mutts...
by Gött August 11, 2012
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