The pity puff is the last toke of a joint. It is presented to the next person in the circle as a consolation offer. Usually it is the least tasteful part of the joint and also the hottest part to smoke. It is therefore offered as a "pity" toke, or "puff".
"There were too many people smoking on one joint, all I got was the pity puff."
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.