Wanktoss is a derivative of 'Wank' (derived from wanker) and 'toss' (derived from tosser). Both are verbs that mean pretty much the same thing: 'to masturbate'. However, when these two words become Wanktoss it can be used in noun form as an insult or as an exclaimation of pain or annoyance.
Steve: Hey, did you see Hank's hairtoday?
James: Yeah that guy is such a Wanktoss!
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.