Extremely tight black pants, that resemble fake leather, or maybe vinyl. Girls used to wear them early 2000-2002, and being slightly glossy, they looked somewhat like they were made from garbage bags. Also referred to as "gbp"
High school girls would walk around in these tight black pants, which usually made their ass look all stretched and squished like an old ladies...someone in your group would say "GBP" and you all knew some broad was wearing the garbage bag pants
by Gorlack August 05, 2010