A portmanteau of "post" and "vacation". In message boards and forums, when a person or group of people who had been posting in a particular thread quite a lot suddenly or slowly stop posting for a period of time, usually with no explanation. During postcations, threadjacking may occur, but is usually crushed by forum moderators.
xxxKewlGai1132xxx: Hey, I haven't seen MeatMuncher521 in this thread for a while.
NotaNEWb: Oh, yeah, he and ShadowXcool are on postcations.
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.