0 to promise the same room, seat, ticket, etc. to more than one person or group:
The room was double-booked so they had to give us a different one.
1 to sell the same room, seat, or share to more than one person:
A customer complained that they had double-booked his room.
21.4 million shares were booked as having been bought, but later were found to have been double-booked.
2 to agree to be at two meetings or events that happen at the same time:
