beacon

noun

1. a signal fire, esp. one on a hill, pole, etc.
2. any light or radio signal for warning or guiding
3. a lighthouse
4. a radio transmitter that sends out signals for the guidance of aircraft, as at night or in fog
5. a person or thing that warns, offers encouragement or guidance, etc.

transitive verb

1. to light up (darkness, etc.)
2. to provide or mark with beacons

intransitive verb