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 dash cam also utilizes a powerful Sony IMX323 sensor, four IR LED lights, and f/1.4 and 1.8 aperture to provide crystal clear night vision. Chris Hachey, BGR, 9 Sep. 2021 A day at the races offers just one aperture into Mauritian culture, beyond the balmy beach resorts. Mary Holland, Robb Report, 4 Sep. 2021 Beyond optical imaging, companies like Cappella Space and Iceye enable a wide range of capabilities from object detection to flood depth measurements using synthetic aperture radar (SAR). Rachel Olney, Forbes, 1 Sep. 2021 Artist James Turrell is building one of his iconic Skyspaces, a room with a roof aperture that transforms the blue yonder into a natural canvas. Condé Nast Traveler, 12 Aug. 2021 The power to determine the purpose of education and codify what is worthy of study was wielded by white men, who viewed education through a white aperture. Melissa Gira Grant, The New Republic, 9 Aug. 2021 However, increasing the pixel count or switching to a wider aperture can dramatically reduce this effect. Paul Monckton, Forbes, 28 June 2021 The telescope China hopes to build, says Deng, could have an aperture—the diameter of the telescope’s light-gathering lens or mirror—of 100 feet and be the world’s largest, at least for a short time. Corryn Wetzel, Smithsonian Magazine, 19 Aug. 2021 Bergman then overlaid synthetic aperture radar and optical imagery from the European Space Agency’s Sentinel-1 and -2 satellites onto the suspicious AIS pings. Mark Harris, Wired, 29 July 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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Last Updated

15 Sep 2021

Cite this Entry

“Aperture.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/aperture. Accessed 26 Sep. 2021.

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More Definitions for aperture



English Language Learners Definition of aperture

: a hole or small opening in something
: 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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