when you buy a sweater that is too big for your actual size
thus giving you a lot of extra cloth
producing the effect that you have a lot of fat
when you actually have sweater fat
Person 1: "Dude go do some jump ropes"
Person 2: " ugh..it's annoying with all this sweater fat"
When an individual wears many layers of clothing to stay warm from the winter frost and ends up looking bulky.
Wil: "Damnnn..did Sarah gain weight?"
Kate: "No, that's just her sweater fat."