A pump cover is any type of baggy clothing that covers up your temporary pump (muscle swelling) during your work out. A pump cover is often trackpants and/or a hoodie.
You often only wear a pump cover when you start out your work out in the gym. It is believed wearing a pump cover makes you sweat more and warm up faster. Once someone has done their first set the pump cover often comes off.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.