/awl"nuy"teuhr/ , n. Informal.
1. something that lasts, is available, or is open for business throughout the night: The poker game turned into an all-nighter. Are any of the grocery stores all-nighters?
2. an act of staying up all night, as to study or finish a task: I had to pull an all-nighter to get the paper done on time.
[ 1890-95; all night + -ER 1 ]