Viewer
WordNet
noun
(1) An optical device for viewing photographic transparencies
(2) A close observer; someone who looks at something (such as an exhibition of some kind)
"The spectators applauded the performance"
"Television viewers"
"Sky watchers discovered a new star"
WiktionaryText
Noun
- Someone that views some spectacle; an onlooker or spectator
- Someone who watches television
- Any optical device used to view photographic slides
- A program that displays the contents of a file of digital images; an image viewer or file viewer