fidelity

fih-DEL-ih-tee /fɪˈdel.ə.ti/
nounC1GRESATGMAT
formalliterary

Faithfulness to a person, cause, or belief, demonstrated by continuing loyalty and support; also refers to the accuracy of a copy or reproduction.

Often carries a moral or romantic weight, implying long-term devotion or technical precision.

The story behind the word. Derived from the Latin 'fidelitas', from 'fidelis' (faithful), which traces back to 'fides' (faith). In the mid-20th century, the term was adopted by audio engineers to describe 'high fidelity' (hi-fi) sound reproduction.

Word relationships

  • loyalty: Loyalty is a general term for devotion, while fidelity often implies strict adherence to a specific vow, duty, or standard of precision.
  • allegiance: Allegiance is typically political or institutional, whereas fidelity is more personal, moral, or technical.
  • infidelity: Infidelity refers specifically to unfaithfulness, especially in a marriage or romantic relationship.
  • treachery: Treachery involves active, harmful betrayal of trust rather than just a failure to remain faithful.

Commonly confused with

  • fealty: Fidelity is a broad term for faithfulness, whereas fealty is a specific, historical term for a vassal's sworn loyalty to a feudal lord.

Word family

  • infidelity (noun): The action or state of being unfaithful.

Collocations

  • marital fidelity
  • high fidelity
  • fidelity to duty

Idioms & expressions

  • true blue

Example sentences

  • "The couple swore a lifetime of fidelity to one another during their vows." Describing marital devotion.
  • "The new speakers reproduce the classical recording with astonishing fidelity." Referring to high-quality audio reproduction.

Memory hook

Fidelity sounds like 'Fi-Del'—think of a dog named Fido, the classic symbol of faithful loyalty. FIDO-lity: Fido the dog is the ultimate symbol of fidelity.

When not to use

Avoid using for casual, short-term agreements where simple 'reliability' is more appropriate.

Fun facts

  • The motto of the United States Marine Corps, 'Semper Fidelis' (often shortened to 'Semper Fi'), translates to 'Always Faithful'.

Related words

confide, fealty

Explore more words

infidelity, devotion, disloyal

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