A gang call of the Bloods which is supposed to imitate a gun noise. The alternate form is BLAT. Not to be confused with brat, a spoiled child.
In contrast, the Crips have ccccclat or clat, which is also supposed to be a gunshot sound. Other Blood gang calls include "suwoop" and "CK".
Guy: That lil boy is a brat.
Crip: A WHAT?
Guy: He's, uh, very spoiled.
Crip: Oh, I thought you said he was a slob.
Suddenly a Blood ran in and shouted, "Brrrrrrat! SUH WOOP!"
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.