stay up phrasal verb ( see also ↑ stay )
to not go to bed at the time you would normally go to bed:
We stayed up all night talking.
I let the kids stay up late on Fridays.
stay up phrasal verb ( see also ↑ stay )
to not go to bed at the time you would normally go to bed:
We stayed up all night talking.
I let the kids stay up late on Fridays.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012