A song that, when played at a club, party, or anywhere else, is effectively like blowing a dog whistle. Only instead of dogs, it immediately draws every fat girl directly to the dance floor to shake their fat-asses around, believing that the song is giving them permission to do so, and that everyone somehow wants to see it.
When I heard the opening lyrics to "Baby Got Back" being played, I rushed away from the dance floor to avoid the inevitable rush of fatties and the resulting nausea that would be induced in most guys as the cows blissfully shook their asses around.
A girl with an ass that sticks out in a specific matter, usually the girl contains an ass like a semicircle sticking out from the side. Most appealing when the girl has a slim waist, and definitely MY KIND OF GIRL.