What does 6PBF mean?

6PBF meaning in Urban Dictionary

A 6PBF is an acronym for six pack of straight back Flaps. Whenever an obese woman is putting on a super taut shirt along with her back flaps show-through, she reveals her 6PBF. The 6PBF contains the initial two flaps on top of the bra, the main two moves underneath the bra, not to mention the muffin top over the pants. Also referred to as the Half Rack of Back Flaps(HRBF).