The action of accidentally leaving something behind on an airplane, most notably in the seatback storage area in front on you.
I was reading a great article in Wired, but I seatbacked it on the flight back from Kona.
by johntex December 08, 2004
When leaving a chair, you can say "I call seatback" and no one else in the room can take the seat away from you. Similar to saying, "I call shotgun" when approaching a car.
No way, you can't sit there, I called seatback!"
by Jamie Kozma March 11, 2006
Anouncing that you are reserving your seat when you getting up to get something.
Jason you dumbass,I'm getting a drink. Seat back.
by Jason you dumbass November 20, 2005
when leaving a seat calling seatbacks before someone else sits in it gets you your seat back upon returning. If you sit somewhere else, or go outside than seatbacks is nullified.
Get up out my seat, I called seatbacks 'fo you sat down
by lesteveman September 05, 2006