flasher

Short definition from Wiktionary

Noun

1. 1
   Anything that flashes, especially a device that switches a light on and off.
2. 2
   An indicator or turn signal.
3. 3
   Someone of great accomplishments, or brilliant appearance.
4. 4
   Someone who exposes themselves indecently; someone who ‘flashes’ their genitals.
5. 5
   A software developer who uses the Flash multimedia technology.

Proper noun

1. 1
   A city in North Dakota.