Someone who is secure with being overweight. A fat person who is so confident with themselves, that they are impervious to any demeaning fat terms (fat jokes).
Person 1--- Look how fat that guy is , if I was that fat, I would never take my shirt off at the pool, what is wrong with him?

Person 2---- nothing, he just doesn’t give a shit about what others think, he’s a Fatmug.
by cashmills January 23, 2010
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