a rather large man/woman that is having sex with another very large person; a disturbing creeper that stalks large men that is also quite large and also male.
Did you see that fat fuck? He's been following us all morning!
The proper name of any kind of food that will make one's butt fat.
Fat-Butt in a pan (Brownies), Fat-Butt in a bag (Chips), Fat-Butt in a Bucket (KFC) Fat-Butt in a flat box (Pizza), and Fat-Ass-In-A-Glass (Margarita) etc.
"Pass me another slice of that Fat-Butt. Wow, this is the best Fat-Butt I've had in a long time! No one makes Fat-Butt better than your Mom!"