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


hole, opening, orifice, perforation

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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

Synthetic aperture radar imagery from Ursa Space Systems shows a similar level of devastation on the Island of Grand Bahama. Andrew Freedman, Washington Post, "Satellite images show the destruction of Dorian in the Bahamas," 5 Sep. 2019 Like Dickens, Winslow widens the aperture to include a multitude of characters. Douglas Preston, The New Yorker, "Briefly Noted," 27 Aug. 2019 The YouTube generation of new comedians challenged the dynamics, structure and aperture of traditional cinematic comedy. Suraj Yengde, Quartz India, "In the politically impotent Indian comedy scene, Dalit humour is a class apart," 8 Aug. 2019 The story’s aperture widens to capture how black students live at Nickel under its sadistic superintendent, even turning toward the future to take in a survivor’s account of the world beyond the school’s walls. Sam Sacks, WSJ, "Fiction: Colson Whitehead Is One of the Finest Novelists in America," 12 July 2019 What Wide Area Motion Imagery does is expand the aperture. Lila Maclellan, Quartz, "The Pentagon is testing powerful mass-surveillance balloons above six US states," 3 Aug. 2019 This week’s session will explore aperture and differential focus in creating images. Houston Chronicle, "The Go List: Sad Summer Festival, Felipe Esparza," 3 July 2019 The main camera has an aperture of f/1.6 and optical image stabilization. Dallas News, "OnePlus 7 Pro is a flagship phone priced way below the competition," 11 July 2019 Vandebergh captured his photos with his satellite photography rig, consisting of a 10-inch F/4,8 aperture Newtonian telescope with an Astrolumina ALccd 5L-11 mono CMOS camera. Kyle Mizokami, Popular Mechanics, "Space Photographer Snaps Pictures of Secretive X-37B in Orbit," 9 July 2019

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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Statistics for aperture

Last Updated

13 Sep 2019

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Time Traveler for aperture

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

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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

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Comments on aperture

What made you want to look up aperture? Please tell us where you read or heard it (including the quote, if possible).


authorized for issue (as a bond)

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