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.

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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

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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

Explanation

Fidelity is the quality of being faithful or loyal. Dogs are famous for their fidelity. Fidelity comes from the Latin root fides, which means faith, so fidelity is the state of being faithful. Marital fidelity is faithfulness to your spouse. If you're a journalist, your reports should have fidelity to the facts. Someone without fidelity to a religion or group belief is called an infidel.

Example Sentences

“Black Bag” tore up spy movie conventions with its emphasis on fidelity in the field, becoming one of the genre’s most scintillating new films in years.

From Salon • Apr. 17, 2026

Inside, standing 43 inches tall, a silver speaker from Takahiro Miyashita’s brand TheSoloist vibrates high fidelity through the showroom.

From Los Angeles Times • Apr. 17, 2026

Rigetti plans to enhance its Cepheus system to achieve a median 99.5% two-qubit gate fidelity later this year.

From Barron's • Apr. 8, 2026

How do you get it there with better fidelity and a lower cost?

From The Wall Street Journal • Mar. 28, 2026

A military surgeon would have admired the clinical fidelity of the artist’s rendition of all Christ’s wounds—the spear wound, the thorn wounds, the holes that were made by the iron spikes.

From "Slaughterhouse-Five" by Kurt Vonnegut

Related Words

• devotion
• loyalty