viewer

From Middle English vewer; equivalent to view +‎ -er.

viewer (plural viewers)

1. Someone who views a spectacle; an onlooker or spectator.
   • 2010, Antonio Saggio, A Secret van Gogh: His Motif and Motives, →ISBN, 11:

     This sensation of an object becoming alive is a characteristic that, I believe, seizes all viewers of a van Gogh. The Bible goes beyond being a simple still-life object to become a living thing, an expression of strength, an existence that emanates from itself, beyond the painting surface to participate in our very lives.

2. Someone who watches television.
3. Any optical device used to view photographic slides.
4. (computing) A program that displays the contents of a file.
5. (mining, historical) The manager of a colliery, who directs its workings and ventilation.

• underviewer

• review

viewer

1. Alternative form of vewer