To stay even or ahead.
To continue with (work, etc).
To maintain; to preserve; to prevent from deteriorating.
To ensure that one remains well-informed about something.
To prevent someone from going to bed or to sleep
To remain at a certain place instead of moving on.
To stand about without any aim or purpose; to stand about idly.
For an aircraft to remain in the air near a target.
A standing or strolling about without any aim or purpose.