Observer

1. (n.) One who observes, or pays attention to, anything; especially, one engaged in, or trained to habits of, close and exact observation; as, an astronomical observer.

2. (n.) One who keeps any law, custom, regulation, rite, etc.; one who conforms to anything in practice.

3. (n.) One who fulfills or performs; as, an observer of his promises.

4. (n.) A sycophantic follower.

Thesaurus Entries

TV-viewer, ace, air force, beholder, bird-watcher, bomber pilot, bystander, combat pilot, drugstore cowboy, examinant, examiner, eyewitness, fighter pilot, flyboy, gaper, gazer, gazer-on, girl-watcher, goggler, inspector, investigator, kibitzer, looker, looker-on, military pilot, naval pilot, ogler, onlooker, perceiver, percipient, scrutineer, seer, sidewalk superintendent, spectator, spectatress, spectatrix, suicide pilot, televiewer, television-viewer, tester, video-gazer, viewer, visitator, visitor, watcher, witness