Observer /(?)/

Ob·serv·er

Observer

n.
  1. 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.
    The observed of all observers.
    Careful observers may foretell the hour, By sure prognostic, when to dread a shower.
  2. One who keeps any law, custom, regulation, rite, etc.; one who conforms to anything in practice.
    These . . . hearkened unto observers of times.
    — Deut. xviii. 14.
  3. One who fulfills or performs; as, an observer of his promises.
  4. A sycophantic follower. [Obs.]