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Etymology and origin of the English word parity

Pronunciation

  • UK: /ˈpæɹɪti/[1]

parity1 equality

Confidence
Established
Formation
Borrowing
First attested
1572
Borrowed from
Middle French parité
Ultimate origin
Latin pār

Etymology

The noun meaning equality is borrowed from Middle French parité[2][3][4][5] or directly borrowed from Late Latin paritās (“equality”),[2][3][5][6] from Latin pār (“equal”) and the suffix -tās.[5][2][7] The French word is recorded from 1345,[5] and Etymonline dates it to the 14th century;[3] the Anglo-Norman form parité is recorded from about 1292.[8] In post-classical Latin the word meant equality from the early 4th century, and for the evenness of a number from the 5th.[5] The Latin adjective is also the source of par, pair and peer.[6][2][3]

Earliest recorded meaning

Equality of rank or status, especially the absence of any distinction between the ministers or members of a church: 1572.[5][2][9]

Semantic evolution

The early sense of equal rank belonged to church disputes: the OED's specific sense is the equality of ministers in a church,[5][9] and Johnson (1755), defining the word as "equality; resemblance", quoted a passage on the Scottish parity of presbyters.[10] From 1609 it meant equality in amount or number.[5][9] From 1612 it meant likeness or analogy, especially in the phrase parity of reason, which the OED compares with the Latin parī ratiōne.[5] Etymonline dates the sense of being on a level to the 1610s.[3] The obsolete sense "evenness of a number" (before 1620) was taken up again in mathematics in 1879, for the property of an integer of being odd or even.[5][9] Finance gave the word its senses of equivalence in another currency (1860), of a fixed legal ratio between gold and silver coins (1895), of an agreed farm price (1941) and of an exchange rate fixed through the International Monetary Fund (1945).[5][9] Physicists used it from 1939 for a property of wave functions,[5][9] and the 1955 sense of equal strategic strength between hostile powers first referred to the United States and the Soviet Union.[3][5] In British education, parity of esteem is the equal standing of schools of comparable kinds.[4][5]

Timeline

  • 1572 – equality of rank or status.[5][2]
  • 1609 – equality in amount or number.[5][9]
  • 1612 – likeness, analogy, as in parity of reason.[5]
  • before 1620 – the evenness of a number (obsolete).[5][9]
  • 1860 – equivalence in another currency.[5][9]
  • 1879 – in mathematics, the property of being odd or even.[5][9]
  • 1895 – a legal ratio between coins of different metals.[5]
  • 1939 – in physics, a property of a wave function.[5][9]
  • 1943 – the equal standing of comparable schools.[5]
  • 1955 – equal strategic resources of rival powers.[5][3]
  • 1966 – in computing, short for parity bit.[5][9]

Meanings

Noun

  1. Equality of rank, status, pay or value: The nurses sought pay parity with other health workers.[11][7][12]
  2. Close equivalence, likeness or analogy.[11][7] By parity of reasoning: by the same line of argument.[5]
  3. Equal military or strategic strength between rival powers.[12][5]
  4. (finance) The value of one currency in terms of another at a fixed rate of exchange; also, equality between the prices of a commodity or security in different markets.[11][7][12]
  5. (mathematics) The property of an integer of being odd or even.[5] In computing, the use of an odd or even number of bits as a check, as with a parity bit.[5]
  6. (physics) A property of a system or wave function according to whether it stays the same or changes sign under reflection of the space coordinates.[11][5]

Word family

  • imparity
  • parity bit

parity2 having given birth

Confidence
Established
Formation
Derivation
First attested
1877 Transactions of the Obstetrical Society
Ultimate origin
Latin pariō

Etymology

The medical noun is formed from English -parous + -ity,[5][4][7][13] from the Latin combining form -parus,[5] which is from Latin pariō (“to give birth, bring forth”);[12][14] the OED thinks it was probably modelled on multiparity and primiparity.[5] The Oxford Dictionary of English describes parous here as a back-formation from adjectives ending in -parous.[13] The American Heritage Dictionary traces the Latin verb to the root Proto-Indo-European *perə-.[12]

Earliest recorded meaning

The fact of having given birth, or of having given birth a given number of times: 1877, in the Transactions of the Obstetrical Society.[5][7]

Semantic evolution

The word has stayed a medical term.[4][5] The Shorter Oxford separates the condition of having borne children (late 19th century) from the number of times a woman has conceived or given birth, which it dates to the early 20th century;[4] Merriam-Webster counts multiple births as one and compares gravidity, the number of pregnancies.[7] The adjective parous is recorded later than the noun.[5]

Timeline

  • 1877 – the condition of having given birth, or the number of births.[5][7]
  • early 20th century – the number of times a woman has conceived or given birth.[4]

Meanings

Noun

  1. (medicine) The fact or condition of having given birth.[7][4][5]
  2. (medicine) The number of times a woman has given birth, with multiple births usually counted as one: Her chart recorded a parity of three.[7][4][5]

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b c d e f g h Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  5. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z 27 28 29 30 31 32 33 34 35 36 37 38 39 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  6. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  7. ^ a b c d e f g h i j Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  8. ^ Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
  9. ^ a b c d e f g h i j k l Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
  10. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
  11. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
  12. ^ a b c d e The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  13. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
  14. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House

Related etymologies

Cite this entry

“Parity.” Etymologically, 31 Oct. 2026, etymologically.com/en/parity. Accessed 31 Oct. 2026.

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