A tendency for the gluteus to be ever there.
See Also: Jumpulous
Patient: Doctor B I'm having difficulty fitting into my jeans.
Doctor B: I'm afraid you have a severe case of
B.A.S. Very advanced, the best I've ever seen!
Patient: B.A.S.?! OMG Doctor, what is that?!
Doctor B: BIG AYASS SYNDROME!!
(big ass syndrome)