Overbooking is taking more bookings than there are rooms. Deliberate overbooking, an overbooking policy, blame the overbooking.
Airlines and hotels do it on purpose, because a predictable share of bookings never turn up, and the mathematics usually works. When it does not, somebody is bumped, and passengers in Europe have a legal right to compensation when that happens.
1nounoverbookingTaking more bookings than there are rooms.
“Because of overbooking, the airline asked for volunteers to take a later flight.”
overbooking is a practice.
overbook comes from over- + book.
Etymology from Wiktionary, CC BY-SA