What is Run down?
Run down is (verb) 1. to go down something quickly on foot She ran down the stairs two at a time. Can you run down to the village and buy me some bread? 2. (of clock, machine) to stop working or go slower because of lack of power The clock has run down it needs a new battery. 3. to criticise someone It’s not fair to run him down when he’s not there to defend himself. 4. to reduce the quantity of something We’re running down our stocks of coal before the summer. 5. to knock down with a vehicle She was run down by a car which did not stop.
source: Easier English, Student Dictionary Upper Intermediate Level