1. One that views, especially an onlooker or spectator.
2. Any of various optical devices used to facilitate the viewing of photographic transparencies by illuminating or magnifying them.
3. A person who watches television or movies: viewers of prime-time shows; viewers of action movies.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.