Synonyms of the word

viewer

• n. Someone who views a spectacle; an onlooker or spectator.
• n. Someone who watches television.
• n. Any optical device used to view photographic slides.
• n. (computing) A program that displays the contents of a file.
• n. (mining, historical) The manager of a colliery, who directs its workings and ventilation.

beholder

• n. Someone who observes or beholds; an observer or spectator.
• n. (fantasy) A fictional monster in roleplaying games, a floating orb of flesh with a large mouth and many…

looker

• n. (literally) One that looks (actively), watches.
• n. One having a specific look, appearance.
• n. (slang) Someone or something who is remarkably good-looking.

observer

• n. One who makes observations, monitors or takes notice.
• n. One who adheres or follows laws, guidelines, etc.
• n. A person sent as a representative, to a meeting or other function to monitor but not to participate.
• n. A country or other entity which has limited participation rights within an organization.
• n. (military) A crew member on an aircraft who makes observations of enemy positions or aircraft.
• n. (military) A sentry etc. manning an observation post.

perceiver

• n. Agent noun of perceive; one who perceives.

percipient

• adj. Having the ability to perceive, especially to perceive quickly.
• adj. (psychology, education, dated) Perceiving events only in the moment, without reflection, as a very young…
• n. (philosophy, psychology) One who perceives something.
• n. (parapsychology) One who has perceived a paranormal event.

spectator

• n. One who watches an event; especially, one held outdoors.

watcher

• n. someone who watches or observes.
• n. someone who keeps vigil.
• n. a guard.

witness

• n. (uncountable) Attestation of a fact or event; testimony.
• n. (countable) One who sees or has personal knowledge of something.
• n. (countable) Someone called to give evidence in a court.
• n. (countable) Something that serves as evidence; a sign.
• v. (transitive) To furnish proof of, to show.
• v. (transitive) To take as evidence.
• v. (transitive) To see or gain knowledge of through experience.
• v. (intransitive, construed with to or for) To present personal religious testimony; to preach at (someone)…
• v. To see the execution of (a legal instrument), and subscribe it for the purpose of establishing its authenticity.