Real Dictionary

run down
phrasal verb: If people run down an industry or an organization, they deliberately reduce its size or the amount of work that it does.
phrasal verb: If you run people or things down, you criticize them strongly.

run down in British English
not wound and therefore not running, as a spring-operated clock
to cause or allow (an engine, battery, etc) to lose power gradually and cease to function or (of an engine, battery, etc) to do this
to cease to run, or stop operating, as a mechanical device, through lack of power
to strike and fell or overturn, esp. to drive a vehicle into (someone)
adjective: fatigued; weary; exhausted
adjective: tired or slightly ill
adjective: tired; exhausted
noun: a brief review, résumé, or summary

run-down
If someone is run-down, they are tired or slightly ill.