FIDEL'ITY, noun [Latin fidelitas, from fides, faith, fido, to trust. See Faith.] 1. Faithfulness; careful and exact observance of duty, or performance of obligations. We expect fidelity in a public minister, in an agent or trustee, in a domestic servant, in a friend. The best security for the fidelity of men, is to make interest coincide with duty. 2. Firm adherence to a person or party with which one is united, or to which one is bound; loyalty; as the fidelity of subjects to their king or government; the fidelity of a tenant or liege to his lord. 3. Observance of the marriage covenant; as the fidelity of a husband or wife. 4. Honesty; veracity; adherence to truth; as the fidelity of a witness.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI