Meaning: Hit a pedestrian with a vehicle
Example: The minicab RAN him DOWN on the zebra crossing.
Meaning: Lose energy or power
Example: You should only recharge the battery when it has fully RUN DOWN.
Meaning: Criticise, disparage
Example: They're always RUNNING me DOWN and I am sick and tired of it.
Meaning: Find the source or origin of something
Example: The police RAN DOWN all the leads they had and caught them.