Etymologically
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curvature

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Pronunciation

  • US: /ˈkɜɹ.və.tʃəɹ/[1]

Etymology

It is borrowed from Latin curvātūra (“curved shape, bend”),[2][3][4] from curvātus, the past participle of curvō (“to bend”), and the suffix -ūra.[2][4][5] The verb is from curvus (“crooked, curved, bent”),[4][3] from Proto-Indo-European *sker- (“to turn, bend”).[3][4] The Shorter Oxford and the Oxford Dictionary of English take the word through Old French,[6][7] while the OED treats it as a direct borrowing from Latin and compares curvature, recorded before 1544, and courbure.[2] It is related to curve.[3][7]

Earliest recorded meaning

A curved part of something, a curve: perhaps before 1425, in a translation of Guy de Chauliac's Grande Chirurgie.[2] Dictionary.com dates the word to late Middle English,[8] while Merriam-Webster gives 1603 and Etymonline the 1660s.[5][3]

Semantic evolution

The abstract sense, the action of curving or the state of being curved, is recorded from before 1460, in Knyghthode and Bataile;[2] Etymonline defines its 17th-century use as continuous bending, the essential character of a curve.[3] Johnson (1755) glossed it as crookedness, inflexion, or manner of bending.[9] Medicine used it from 1762 for an abnormal curve of the spine.[2] Mathematics made it a measured quantity: the amount by which a curve departs from a straight line, from 1710 in Harris's Lexicon Technicum,[2] with the radius of curvature from 1712.[2] In non-Euclidean geometry it was applied to space itself from 1873.[3][2] A verb curvature, to curve, is recorded once, before 1811.[2]

Timeline

  • c. 1425 – a curved part of something, a curve.[2]
  • before 1460 – the action of curving; the state of being curved.[2]
  • 1710 – in geometry, the degree to which a curve deviates from a straight line.[2]
  • 1712 – radius of curvature.[2]
  • 1762 – an abnormal curve of the spine.[2]
  • 1873 – the curvature of space, in non-Euclidean geometry.[2][3]

Meanings

Noun

  1. The act of curving, or the state or degree of being curved.[5][2][10]
  2. A curved part of something; a bend.[5][10][2]
  3. (medicine) An abnormal curving of a part of the body, as in curvature of the spine.[10][2]
  4. (geometry) The rate at which a curve departs from a straight line, or a surface from a plane, measured by the turning of the tangent along the arc; for a circle, the reciprocal of its radius.[10][5][2]
  5. (geometry) The degree to which a space or manifold differs from Euclidean space.[2]

Word family

  • center of curvature
  • radius of curvature
  • curve
  • curvilinear
  • curvaceous

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q r s t u Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b c d The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  5. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  6. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  7. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
  8. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  9. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
  10. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins