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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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 For the perfect exposure, Shih says it’s usually best to use a larger aperture, slow shutter speed, and appropriate ISO setting. Stacey Leasca, Travel + Leisure, "How to Photograph Fireflies on Your iPhone Like a Professional," 11 July 2020 The system uses the traditional LCD display combined with an LCD aperture grille that sits a few millimeters ahead of the display. Roberto Baldwin, Car and Driver, "2021 Mercedes-Benz S-Class Gets Updated Infotainment, 3D Display," 8 July 2020 Gskyer astronomical refracting travel telescope ($95.99) with 70mm aperture, 400mm (f/5.7) focal length, phone adapter and wireless remote that lets beginners explore the stars and moon can be transported in its carry bag. oregonlive, "Amazon best sellers – what everyone is buying on sale for summer and maybe you should too," 5 July 2020 Estimating the height above ground and aperture of the cloaca—the opening through which penguins defecate—was equally simple. Jennifer Ouellette, Ars Technica, "The explosive physics of pooping penguins: they can shoot poo over four feet," 4 July 2020 The first Bentayga had a more conventional trunk aperture dividing the rear light units, which the company clearly reckons wasn’t sufficiently redolent of Bentley's other models. Mike Duff, Car and Driver, "2021 Bentley Bentayga Gets Big Style and Content Upgrade," 30 June 2020 Each aperture is spaced equally to provide access to available light. Matt Bean, Sunset Magazine, "Sunset Loves: I Tried Vertical Gardening and Now the Neighbors Love Me," 12 June 2020 The latest in a long line of rough-and-tumble pocket cams from Olympus, the TG-6 pairs a waterproof, crushproof exterior with a wide-aperture lens that does exceptionally well in low light—on dry land or up to 50 feet underwater. Jess Grey, Wired, "The Top 3 Rugged Cameras for Daredevil Shooters," 21 Apr. 2020 Set into the walls, apertures — barred like the windows of a jail cell — appear to look out onto a clear sky. Kelsey Ables, Washington Post, "In an endless news cycle, art at Glenstone both echoes and quiets the chaos," 30 Jan. 2020

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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Statistics for aperture

Last Updated

16 Jul 2020

Cite this Entry

“Aperture.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/aperture. Accessed 11 Aug. 2020.

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More Definitions for aperture


How to pronounce aperture (audio)

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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