to fail to keep up (with)
Used other than figuratively or idiomatically: see fall, behind.
To be late (for a regular event)
To be progressively below average in performance.
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.