A Bust Down is a small part of a cigarette (usually less than one half) that one gives away.
"Bust me down"
"You gave that guy a bust down? He stays bumming cigarettes.."
1. usually used to refer to a female
2. is a derogatory term for a female
3. indicates that she is sexually promiscuous with no discretion
4.simply, a ho
5. etc, etc, etc
someone that will have sex with you and a friend or friends with no hesatation. Must ninfos are bus downs