The distance by which a girls booty stops you from going any further when clapping in doggy and therefore prevents all of the meat stick from entering. Big bunda means a large NDBR and no bunda means a small/non-existent NDBR.
“Bro her no dick booty restriction zone went crazy; her bum was so big I was just clapping bare cheeks, not actual vagina”
“That’s crazy my g, I’m yet to experience a 100% no dick booty restriction zone stillllll’