look up any word, like turnt:
 
1.
when you don't have a full blown boner
i was looking up her skirt and i got a b flat
by xtimmiex June 03, 2007
 
2.
adj: musicians' slang meaning ordinary or common, so-so; unimpressive.
"That restaurant was pretty B-flat; I've had better."
by Slideman October 30, 2006
 
3.
A fart that has a lot of bass, as opposed to being a squeeker
Jim: Holy shit Mark, that was one stinky fart.

Mark: Yeah, it was a B Flat.
by CMBC April 07, 2011