Its is to be lost in space, to have very little brain function and have no awareness of what is going on around you. Commonly happens when a person is stoned/and or driving.
Person One: "Did you hear what I just said?"
Person Two: "No sorry I was gapping out"
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.
"Base we've got some square groupers floating outside of Miami harbor."