Wiktionary
seat only
n. (context travel UK Ireland dated English) A package holiday rate without confirmed accommodation reservations, or using a dummy reservation, enabling the tour operator to sell charter airline seats in competition with the airlines.
Usage examples of "seat only".
Though Nokias was the senior mage in this quarter, Plennafrey had heard he held the seat only because Iranika didn't want it.
He was no longer the man that had climbed out of the driver's seat only a few hours before.
With a shudder that told of overtaxed muscles giving up a struggle, Morgan slumped, held upright in his seat only by its harness.