OBSERV'ER, noun s as z. 1. One who observes; one that takes notice; particularly, one who looks to with care, attention or vigilance. Careful observers may foretell the hour, by sure prognostic, when to dread a shower. Creditors are great observers of set days and times. 2. A beholder; a looker on; a spectator. 3. One who keeps any law, custom, regulation or rite; one who adheres to any thing in practice; one who performs; as a great observer of forms; an observer of old customs. 4. One who fulfills or performs; as, he is a strict observer of his word or promise. 5. One who keeps religiously; as an observer of the sabbath.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI