transitive verb
1.
a. : to collide with and knock down (as with an automobile)
ran down an old man in the rain
b. : to run against and sink
ran a fishing boat down in the harbor
2.
a. : to chase until exhausted : pursue until overtaken or captured
finally ran the fugitive down in a blind alley
b. : to find by search : trace the source of
had quite a time running down the technical words — Tom Marvel
c. : to tag out (a base runner) between bases
3. : disparage
nags her husband and runs him down in company
4. : to cause to diminish in value or quantity
run a stock down
intransitive verb
1. : to cease to operate because of the exhaustion of motive power
that clock ran down hours ago
2. : to decline in physical condition
his health ran down to a dangerous level
the railroads have been permitted to run down alarmingly
3. Britain , of a stream : to fall to normal level after a flood