fidelity

Etymology

It is inherited from Middle English fidelite,^[2][3][4] borrowed from Middle French fidélité,^[3][4][5][6] which Etymonline and the MED take as Old French,^[7][2] or directly borrowed from Latin fidēlitās (“faithfulness, loyalty”).^{[8][9][10][11]} The Latin noun is formed from fidēlis (“faithful”), from fidēs (“faith”),^{[6][7][12][3]} from Proto-Indo-European *bʰeydʰ- (“to trust, confide, persuade”).^[7][12] Klein relates the Latin to foedus (“compact, treaty”), and the root to Old English biddan (“to ask”).^[13] fealty comes from the same Latin noun through Old French.^[9][5][10]

Earliest recorded meaning

Faithfulness, trust; also fealty and allegiance: probably before 1425, in a translation of Higden's Polychronicon.^[3][2] The OED's first record, for faithfulness or loyalty to a person or bond, is from 1509, in Alexander Barclay's Shyp of Folys.^[6]

Semantic evolution

From faithfulness to a lord, party or bond the word spread in the early 16th century to honesty and truthfulness (1534–1709) and to a pledge or word of honour, as in by my fidelity (1531–1616).^[6] Johnson (1755) gave "honesty; veracity" as its first sense.^[11] Faithfulness in marriage is recorded from 1694.^[6] From 1708, in Pope, it was used of a description or translation that matches its original,^[6] and since 1878 of how closely a reproduced sound or picture matches the original,^[6][7] the sense behind high fidelity and hi-fi.^[6] Ecologists have used it since 1932 for how closely a species is tied to a plant community.^[6]

Timeline

• probably before 1425 – fidelite, faithfulness, allegiance.^[3][2]
• 1509 – faithfulness, loyalty.^[6]
• 1531 – a pledge, word of honour (obsolete by 1616).^[6]
• 1534 – honesty, truthfulness (obsolete by 1709).^[6]
• 1694 – faithfulness in marriage.^[6]
• 1708 – exactness of a description or translation.^[6]
• 1878 – accuracy of reproduced sound.^[6][7]
• 1880 – fidelity insurance.^[6]
• 1932 – in ecology, the tie of a species to a plant community.^[6]

Meanings

Noun

1. Faithfulness or loyalty to a person, cause or duty: His fidelity to the party never wavered.^[5][14][6]
2. Faithfulness to one's husband, wife or partner.^[5][14][6]
3. Accuracy in detail; close agreement with the facts or with an original: the fidelity of the translation.^[5][14][6]
4. The degree to which a system such as an amplifier or a radio reproduces the sound or picture it receives.^[14][5][6]
5. (obsolete, 1534–1709) Honesty, veracity.^[6][11]

Word family

• high fidelity

Related words

• affidavit
• bide
• bona fide
• faith
• infidel
• nullifidian
• solifidian
• fealty
• infidelity
• confide

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
5. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e f g h i j k l m n o p q r s t u v Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
7. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
10. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
11. ^ a b c Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
12. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
13. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
14. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins