flasher

noun4

1. •
   Anything that flashes, especially a device that switches a light on and off.
2. •
   (slang) Someone who exposes themselves indecently; someone who ‘flashes’ their genitals.
3. •
   An indicator or turn signal.

   • Look here, look at this fire truck! It has flashers and sirens, and if you push the button at the bottom, it moves by itself. — 2019
4. •
   (no longer used) Someone of great accomplishments, or brilliant appearance.

   • Mr Yorke of D'Affrenalli has been introduced to me as a Wit & a Flasher: it was supposed that we were to admire one another's Abilities,—but I fancy the Project failed on both Sides […]. — 1795

noun1

1. •
   (informal) A software developer who uses the Flash multimedia technology.

   • JavaScript is an appealing solution for Flashers because it operates in the same client-side environment […] — 2001