at a run—moving at a running pace:
- Suddenly, there he was, at a run, hurrying my son to unpack the rifle and climb the mountain with him.
on the run—(predic.)—
- Although I am perfectly still, I find myself taking quick short breaths, as if I too am on the run.
2. (also: on the trot) busy moving from one task to another:
- It was vacation, and I shouldn’t feel bad if I am not on the run every minute of the day.
3. (also: on the trot) running away from prison, the police, etc.:
- He went to meet a Franc-Tireur who was on the run after killing several Germans.
4. (of troops) retreating; severely defeated:
- They all believed that this first success should be fully exploited while the enemy was on the run.