the GNU version of the Collaborative International Dictionary of English
n. One who perceives (in any of the senses of the verb).
The Century Dictionary and Cyclopedia
n. One who perceives, feels, or observes.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a person who becomes aware (of things or events) through the senses
Word Usage
"The "conditions" that might prevent us from enjoying aesthetic experience are those that cut off either the artist or the perceiver from the "beauty" of creating and focus his/her attention instead on the purely utilitarian."