streaker vs flasher

streaker and flasher both are nouns.

Word	Noun	Adjective	Verb	Adverb
streaker	Yes	No	No	No
flasher	Yes	No	No	No

As nouns, flasher is a hypernym of streaker; that is, flasher is a word with a broader meaning than streaker:

streaker: someone who takes off all their clothes and runs naked through a public place
flasher: someone with a compulsive desire to expose the genitals

Other hypernyms of streaker include exhibitionist, nude, nude person.

streaker (noun)	flasher (noun)
someone who takes off all their clothes and runs naked through a public place	an electrical device that automatically turns a lamp on and off (as for an advertising display)
	a light that flashes on and off; used as a signal or to send messages
	someone with a compulsive desire to expose the genitals