0 past simple and past participle of double-book
1 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.
Many bass players find extra work by substituting (subbing) for bassists who are double-booked or ill.
Then, a bit later the stylists found out they were double-booked, and that they had to make a different look for their clients' identical twin.
Many cello players find extra work by substituting (subbing) for cellists who are double-booked or ill.
Sheena asked the backing members well in advance to perform for the tour, so that her first choices would not be double-booked.
Gosz handled all of his own bookings, and not being the most attentive businessman, he often double-booked his gigs.