a booty that's tight and just right. its made of muscle but can still jiggle with the rest of em. usually found on people on the track team, a product of their training. most used in reference to females who possess it. Not a fatty, which is a different type of ass. Its a more lean, toned, defined, but attractive ass.
"you think these jeans will fit ?"
"i don't think so, you got that track booty, you gonna have to get a size up"
"dammnnnn you saw that??"
"yea man, im about to smack that ass"
"aight, go head but you might break ya hand on that track booty"
"those panty shorts are riding wayyyy up her ass"
"its cause she got that track booty, only shorts could handle that ass"