fidelity

American  

[fi-del-i-tee, fahy-] / fɪˈdɛl ɪ ti, faɪ- /

noun

plural

fidelities

1. strict observance of promises, duties, etc..

   a servant's fidelity.

2. loyalty.

   fidelity to one's country.

   Antonyms:

   disloyalty

3. conjugal faithfulness.

4. adherence to fact or detail.

5. accuracy; exactness.

   The speech was transcribed with great fidelity.

   Synonyms:

   rigor, faithfulness, precision

6. Audio, Video. the degree of accuracy with which sound or images are recorded or reproduced.

---

fidelity British  

/ fɪˈdɛlɪtɪ /

noun

1. devotion to duties, obligations, etc; faithfulness

2. loyalty or devotion, as to a person or cause

3. faithfulness to one's spouse, lover, etc

4. adherence to truth; accuracy in reporting detail

5. electronics the degree to which the output of a system, such as an amplifier or radio, accurately reproduces the characteristics of the input signal See also high fidelity

---

Related Words

See loyalty.

Other Word Forms

• nonfidelity noun
• unfidelity noun

Etymology

Origin of fidelity

First recorded in 1500–10; late Middle English fidelite (from Middle French ), from Latin fidēlitās, equivalent to fidēli- (stem of fidēlis “loyal,” equivalent to fidē(s) faith + -lis adjective suffix) + -tās -ty ²

Example Sentences

Whatever happens in the near term, the physical infrastructure around AI will likely show fidelity to that trend.

From Barron's • Apr. 3, 2026

Central Command spokesman, said: “I’m not aware that we had any part of that, but I don’t have complete fidelity on everything that’s happening in Iraq.”

From The Wall Street Journal • Mar. 8, 2026

As an impoverished and ailing Mozart struggles to complete his “Requiem” before his death at the age of 35, Salieri is torn between his fidelity to music and his loyalty to his own career.

From Los Angeles Times • Feb. 18, 2026

The researchers also used fidelity measurements to evaluate performance, confirming reliable switching behavior along with high purity of each mode.

From Science Daily • Feb. 4, 2026

I had defeated a car and a mountain as she pondered over my father’s fidelity.

From "I Know Why the Caged Bird Sings" by Maya Angelou

Related Words

• devotion
• loyalty