The definition of a spectator is a person who watches or observes.
A person who watches, esp. one who keeps watch beside a sick or dead person
A person who watches without taking part; spectator
One who is sent to observe and report on events or proceedings without directly participating in them.
One who can give a firsthand account of something seen, heard, or experienced:
Find another word for viewer. In this page you can discover 9 synonyms, antonyms, idiomatic expressions, and related words for viewer, like: spectator, watcher, onlooker, observer, eyewitness, seer, witness, see and looker.