Pronunciation: (dub'ul book'), [key]
1. to overbook by accepting more than one reservation for the same hotel room, airplane seat, etc.
2. to make reservations for (more than one hotel accommodation, seat on a plane, etc.) so as to be certain of obtaining at least one of them.
to make double reservations for passenger space, a hotel room, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.