The word run has many meanings:

1. To move quickly on foot, faster than walking. When you run to catch the bus or run a race at recess, you're moving with both feet leaving the ground between steps. Marathon runners run 26.2 miles, while sprinters run short distances as fast as possible.
2. To operate or function. A car runs on gasoline, a computer program runs when you start it, and a factory runs its machines during business hours. If something runs smoothly, it works without problems. If a watch has run down, its battery or spring has lost power.
3. To be in charge of something. A principal runs a school, making decisions about schedules, rules, and hiring teachers. Parents run a household. Someone might run a lemonade stand, a company, or even a country by running for office.
4. To flow steadily. Water runs from a faucet, a river runs to the sea, and your nose might run when you have a cold. Paint can run down a wall if you apply too much.
5. To extend in a particular direction. A fence might run along the property line, or a road runs through town. A crack runs across a windshield.
6. To continue for a period of time. A play runs on Broadway for months or years. A movie runs for two hours. A special offer might run until the end of the month.

Other expressions include a run of good luck (a continuous streak), a run on a bank (many people withdrawing money at once), or getting a run in your stockings (a line of unraveled fabric). Baseball runners score runs by circling the bases. The phrase in the long run means eventually or over time.