The voluptuous rear end of a person (esp. of an African-American, Caribbean-American and Latinawoman.) May also be used as a pet name for a girl with a well-endowed rear end.
Ricco's girlfriend's pumpkin-butt could not fit into Apple Bottom jeans. Wow, that's pretty big!
A chick with a huge tooter and plenty of cellulite to match. Usually seen on the beach or wearing clothes that are wayy to small for her. Can also be seen on a man but warning - it might cause blindness.
"Wow did you see those chick's pumpkinbuns? She really needs cover those up."