Meaning

noun someone with a compulsive desire to expose the genitals

noun an electrical device that automatically turns a lamp on and off (as for an advertising display)

noun a light that flashes on and off; used as a signal or to send messages

originEtymology tree English flash Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -āriusnom. Latin -āriusbor. Proto-Germanic *-ārijaz Proto-West Germanic *-ārī Old English -ere Middle English -ere English -er English flasher From flash + -er.

Etymology from Wiktionary, CC BY-SA 3.0