fidelity

American  

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

noun

fidelities plural

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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Synonym Usage

See loyalty.

Other Word Forms

Derived Forms

• nonfidelity
  noun
• unfidelity
  noun

Inflected Forms

Nouns

• fidelities
  plural

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

See Examples For:

fidelity fidelities

"Damon's Odysseus is stubborn, overconfident and sacrilegious, but doesn't bear that much resemblance to the conniving, hypocritical egotist of lore who fretted over his wife's fidelity," she noted.

From BBC ● Jul. 15, 2026

“There is ‘an expectation that even the Attorney General must be able to draw the line between political allegiance and fidelity to the people, as well as the fair administration of law,’ ” Williams wrote.

From Slate ● Jul. 14, 2026

The industry relies instead on fidelity, a measure of accuracy that tracks how closely a quantum operation matches its intended target.

From Barron's ● Jun. 22, 2026

The one place they urged some fidelity to the past versions was in the score.

From Los Angeles Times ● Jun. 5, 2026

“Sometimes, unconsciously, Daugherty expressed it, with more fidelity to exactness, ‘a great-looking President.’”

From "Blink" by Malcolm Gladwell

These gate fidelities are well above the threshold needed for certain common error correcting codes, and should enable error detection in larger-scale systems.

From Science Daily ● Sep. 25, 2023

Gates with the highest possible fidelities are essential because quantum errors accumulate exponentially.

From Science Daily ● Sep. 25, 2023

In laboratory experiments, trapped ions have reached fidelities as high as 99.99%, according to a spokesperson for the company.

From Scientific American ● Feb. 13, 2023

Shallow quantum circuits need higher gate fidelities and more stability to limit decoherence.

From Nature ● Mar. 2, 2017

These qualities pervade his essays and his letters, and the latter in particular reveal those ardors and fidelities of friendship which men like Emerson and Thoreau longed after without ever quite experiencing.

From The American Spirit in Literature : a chronicle of great interpreters by Perry, Bliss

Related Words

• devotion
• loyalty