# fidelity

Pronunciation: US say "fi-DEL-i-tee" /fɪˈdɛl.ɪ.ti/; UK

## Noun

1. The degree to which something is accurate or faithfully reproduces an original, as with a sound system, a copy, or a translation.
   - Simple: How exactly something matches or copies the original, like a sound system or a translation.
   - _Engineers tested the amplifier's fidelity by comparing its output signal with the input._
   - _Compressing the video too heavily reduces its fidelity, leaving blocky edges and smeared colors._
2. Faithfulness to a duty, person, cause, or promise; steady loyalty shown in carrying out one's obligations.
   - Simple: Staying loyal to your duties, to a person, or to a cause or promise.
   - _The old steward served the family with a fidelity that outlasted three generations._
   - _The inspector's fidelity to duty earned her the trust of the whole department._
3. Loyalty to one's spouse or partner, including not cheating on them or having extramarital affairs.
   - Simple: Staying loyal to your husband, wife, or partner and not cheating on them.
   - _An affair early in the marriage left her questioning his fidelity for years._
   - _The novel follows a couple whose ideas of fidelity are tested by a long separation._

## Origin

The word entered Middle English in the 15th century from Middle French fidélité, which came from Latin fidēlitās. That Latin noun was built on fidēlis ("faithful"), which comes from fidēs ("faith, loyalty"), a relative of English faith. The ultimate root, *bʰeydʰ- in Proto-Indo-European, meant "to command, to persuade, to trust" and is also related to English bide. Fealty is a doublet.

Source: DictionaryAI, https://dictionaryai.com/define/fidelity (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).