The booty of a female that's hella nice.
A: Large in size
B: Firm and toned
C: Fine quality i.e. nice and "donk" like
The phrase is believed to have originated from the word blap
A- Damn that girl in front of us got a blapper booty!
B- Indeed, that female's butt is of superior quality.
C- If I may interject, I would have to say that you could bounce a quarter off the ass