Stay Up

1. To remain in a place that is higher than ground level.

Examples: How long can an airplane stay up in the air before it runs out of gas?
The flag is raised in the morning, and stays up throughout the day.

2. To remain awake long after your usual bedtime.

Examples: Don’t stay up too late because you have school in the morning.
During summer vacation, kids get to stay up later than usual.

See our complete list of English phrasal verbs.