(adj) Being in a angry mood because of one's obesity and long term exposure to the resultant feelings of societal rejection. In other words, being perpetually pissed off and bitchy because one is a fatty.
Man, I almost got sideswiped by some fatangry chick driving a Ford Festiva. Is there some sort of inverse proportionality rule where the size of the car is inversely proportional to the size of the driver? Cuz, I'd be pissed too if I weighed 350 and had to squeeze into a Fiesta.