Etymologically
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aperture

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Pronunciation

  • UK: /ˈap.ə.t͡ʃə/, /ˈap.ə.tjʊə/[1]
  • US: /ˈæp.ɚˌt͡ʃʊɹ/, /ˈæp.ɚ.t͡ʃɚ/[1]

Etymology

It is inherited from Middle English aperture,[2][3][4] borrowed from Latin apertūra (“an opening”),[5][3][6][7][8] from apertus (“opened, open”), the past participle of aperiō (“to open, uncover”),[3][6][4][9] with the noun suffix -ūra, English -ure.[5][7][8] Collins calls the Latin noun Late Latin,[10] and Barnhart allows that it may have come through Middle French aperture.[11] Etymonline and the American Heritage Dictionary trace the Latin verb to a compound Proto-Indo-European *ap-wer-yo-, of *ap- (“off, away”) and *wer- (“to cover”);[3][6] Merriam-Webster likewise takes it from a prefix akin to ab (“from”) and an assumed verb meaning "to cover", related to weir.[4]

Earliest recorded meaning

An opening, and the making of an opening: about 1425, in the Middle English translation of Chauliac's surgery, which glosses the word "opnyng" and speaks of treating a swelling of the head by aperture.[2][3]

Semantic evolution

The OED, in an entry not revised since 1885, records the word only from 1649, when Jeremy Taylor used it for the opening up of something intricate, a rare sense soon lost;[5][11] the act of opening is recorded from 1669 to 1709, in Holder's Elements of Speech first.[5][12] Johnson (1755) gave both "the act of opening", quoting Holder, and "an open place".[13] The concrete sense, an opening between solid parts, a gap or hole, dates from 1661,[5][12] and was applied to the mouth of a mollusc's shell by 1794.[12] In optics the word has meant, since 1665, the space through which light passes in an instrument such as a telescope, even where there is no material hole,[5][3] and later the diameter of that space;[3][10] in photography it is the opening of a lens that lets light through.[4] An aperture sight on a rifle is recorded from before 1884.[5]

Timeline

  • c. 1425 – an opening; the act of opening, in Chauliac.[2][3]
  • 1649 – the opening up of something intricate (obsolete).[5][11]
  • 1661 – a gap, cleft or hole.[5][12]
  • 1665 – optics, the space through which light passes.[5][3]
  • 1669 – the act of opening (obsolete by 1709).[5]
  • 1794 – the mouth of a mollusc's shell.[12]
  • before 1884 – the opening in a rifle sight.[5]

Meanings

Noun

  1. An opening, such as a hole, gap, crack or slit: Light came in through a narrow aperture in the shutters.[10][4][5]
  2. (optics, photography) The opening in a lens or other optical instrument that controls how much light or other radiation passes through, often adjustable.[10][4][5]
  3. The diameter of such an opening.[10][3]
  4. (zoology) The mouth of the shell of a mollusc.[5]
  5. (obsolete, 1669–1709) The act of opening.[5][4][8]

Word family

  • apertural
  • apertured
  • apertometer
  • aperture-priority
  • aperient
  • aperitive

References

  1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c 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 f g h i j Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  5. ^ a b c d e f g h i j k l m n o p Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  6. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  7. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  8. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  9. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  10. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins
  11. ^ a b c Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  12. ^ a b c d e Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
  13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.