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1.
The bony bump on the back of many dogs' heads. The larger the mutt bump the more likely the dog is a mixed breed or a mutt.
(Harry) Check out this Black Lab I got.
(Larry) Nah, he ain't a Lab.
(Harry) What? How would you know?
(Harry) He's got a big ol' mut bump.
(Harry) His mutt bump doesn't prove he's a mutt.
(Larry) Guess not. But he still ain't a Black Lab.
by vordmeister July 08, 2011