1. for or during the night: to stay overnight.
2. on or during the previous evening: Preparations were made overnight.
3. very quickly; suddenly: New suburbs sprang up overnight.
1. done, made, occurring, or continuing during the night: an overnight stop; an overnight decision.
2. staying for one night: a group of overnight guests.
3. designed to be used on a trip or for a journey lasting one night or only a few nights.
4. intended for delivery on the next day: overnight letters; an overnight package.
5. valid for one night: The corporal got an overnight pass.
6. occurring suddenly or within a very short time: a comedian who became an overnight sensation.
1. Informal.an overnight stay or trip: Our daughter had an overnight at a friend's house.
2. Informal.a permit for overnight absence, as from a college dormitory: She had an overnight the night of the prom.
3. the previous evening.
to have an overnight stay or trip: We'll overnight in Denver, then fly on to San Diego.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.