starer vs viewer

starer and viewer both are nouns.

Word	Noun	Adjective	Verb	Adverb
starer	Yes	No	No	No
viewer	Yes	No	No	No

As nouns, viewer is a hypernym of starer; that is, viewer is a word with a broader meaning than starer:

starer: a viewer who gazes fixedly (often with hostility)
viewer: a close observer; someone who looks at something (such as an exhibition of some kind)

Other hypernyms of starer include looker, spectator, watcher, witness.

starer (noun)	viewer (noun)
a viewer who gazes fixedly (often with hostility)	an optical device for viewing photographic transparencies
	a close observer; someone who looks at something (such as an exhibition of some kind)