A stereotypical american towards whom non-US nationals react with contempt, disgust, hatred or despair. Portmanteau of the words 'murrican and fat.
Laszlo came back exhausted from his 12 hour flight. The murfat next to him had done nothing but noisily gulp down snacks, monopolize the armrest with his greasy body, and threaten to sue the airline because the seats were too small and the chips too salty and the stewards too socialist.
by LonnieTheJew November 04, 2011