Ob-sĕrv'er, n.
n. 1. One who observes, or pays careful attention to, any thing. Careful observers may foretell the hour, By sure prognostic, when to dread a shower. Swift.
Sense 2. Especially, (a.) A sycophantic follower; a parasite. [Obs.] Great ones still have graced To make them sport, or rub them o'er with flattery. Observers of all kinds. Beau. & Fl.
(b.) One actually or habitually engaged in, or trained to habits of, observation; as, an astronomical observer.
Sense 3. One who keeps any law, custom, regulation, or rite; one who adheres to any thing in practice; as, an observer of old customs.
Sense 4. One who fulfills or performs; as, he is a strict observer of his word or promise.
Sense 5. One who keeps religiously; as, an observer of the Sabbath.