Waitlist (noun)

1. A list of people waiting for a service or event, typically a class or a reservation.
2. A list of people who have requested to be notified of availability for a service or event, but have not yet been able to secure a spot.

Origin:

A list of people waiting for a service or event, typically a class or a reservation.

Examples:

1. I put my name on the waitlist for the concert tickets.
2. The class was full, so I had to join the waitlist.
3. The hotel was fully booked, but they put me on the waitlist in case of cancellations.
4. I was number 4 on the waitlist for the conference registration.
5. The waitlist for the new phone release was so long, it was almost impossible to get a spot.