ap·​er·​ture | \ ˈa-pər-ˌchu̇r How to pronounce aperture (audio) , ˈa-pə-, -chər, -ˌtyu̇r, -ˌtu̇r \

Definition of aperture

1 : an opening or open space : hole entered the cave through a narrow aperture
2a : the opening in a photographic lens that admits the light
b : the diameter of the stop in an optical system that determines the diameter of the bundle of rays traversing the instrument
c : the diameter of the objective lens or mirror of a telescope

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Synonyms for aperture


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Examples of aperture in a Sentence

We entered the cave through a narrow aperture. The photograph was taken using a fast shutter speed and a large aperture.
Recent Examples on the Web The laser is built into what is normally the cargo door on the left side of the plane, with its unwinking aperture looking like a large harmless tube. Kyle Mizokami, Popular Mechanics, 25 June 2021 To be clear, pupil size refers to the diameter of the black circular aperture in the center of the eye. Jason S. Tsukahara, Scientific American, 2 June 2021 In the ceiling overhead, a larger-than-life aperture opens to the light. Sara L. Schneider, Robb Report, 21 June 2021 Adding an extra level of flourish, the dial, moon phase aperture and the moon rotating disc are delivered in champlevé enamel, requiring the base metal to be milled out with the recesses filled in with enamel. Paige Reddinger, Robb Report, 16 June 2021 Open up your aperture for talented and skilled people from all over the world. Mary Juetten, Forbes, 6 Apr. 2021 The Skyspace aperture sharpened the sky in a tight edit: Slim wisps of cloud snaked and wound around each other in a primordial ballet. BostonGlobe.com, 27 May 2021 The aperture is closing, and the activist class is rushing to take advantage of what could be a fleeting opportunity. Philip Elliott, Time, 18 May 2021 Experts said that simple word change — coupled with language that broadened the aperture in which prosecutors, judges and juries could examine officers’ actions — will almost certainly reduce the use of physical force by police. Los Angeles Times, 30 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'aperture.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of aperture

15th century, in the meaning defined at sense 1

History and Etymology for aperture

Middle English, borrowed from Latin apertūra, from apertus, past participle of aperīre "to open" + -ūra -ure — more at aperient

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Time Traveler for aperture

Time Traveler

The first known use of aperture was in the 15th century

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Dictionary Entries Near aperture

apertural canal


aperture card

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Statistics for aperture

Last Updated

17 Jul 2021

Cite this Entry

“Aperture.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/aperture. Accessed 27 Jul. 2021.

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More Definitions for aperture



English Language Learners Definition of aperture

formal : a hole or small opening in something
technical : an opening that controls the amount of light that passes through a lens (such as a camera lens)


ap·​er·​ture | \ ˈa-pər-ˌchu̇r How to pronounce aperture (audio) \

Kids Definition of aperture

: an opening or open space : hole


ap·​er·​ture | \ ˈap-ə(r)-ˌchu̇(ə)r, -chər, -ˌt(y)u̇(ə)r How to pronounce aperture (audio) \

Medical Definition of aperture

1 : an opening or open space
2 : the diameter of the stop in an optical system that determines the diameter of the bundle of rays traversing the instrument

More from Merriam-Webster on aperture

Nglish: Translation of aperture for Spanish Speakers

Britannica English: Translation of aperture for Arabic Speakers

Britannica.com: Encyclopedia article about aperture


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