ap·er·ture | \ˈa-pər-ˌchu̇r, 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

That likely means the Note 9 will get the same dual-aperture trick that the Galaxy S9 picked up earlier this year, which was supposed to help the phone better expose for bright environments. Jacob Kastrenakes, The Verge, "Samsung reportedly plans Galaxy Note 9 announcement on August 9th," 1 June 2018 The main addition for 2018 is a new camera, which is expected to have a variable aperture. Ron Amadeo, Ars Technica, "Here’s our first clear look at the Samsung Galaxy S9," 26 Jan. 2018 The Columbia-Class will utilize Virginia-class’ fly-by-wire joystick control system and large-aperture bow array sonar. Kris Osborn, Fox News, "Navy mulls acceleration of first nuclear-armed Columbia ballistic missile sub," 30 May 2018 In exchange for the zoom, the camera’s aperture is changing from f/1.8-2.8 to the somewhat slower f/2.8-4.5. Jacob Kastrenakes, The Verge, "Sony’s RX100 VI adds a long zoom lens to the best compact camera," 5 June 2018 Then, set the aperture on the lens nice and wide — an F-stop of about 1.4 — to let more light hit the camera’s sensor. Rachel Becker, The Verge, "How to capture the eerie nighttime clouds of climate change," 6 July 2018 Also new to the camera is a super bright mode that detects when a scene is too dark for the normal aperture and automatically increases the brightness digitally to capture more detail. Michael Simon, PCWorld, "LG unveils the G7 ThinQ with more screen and an AI-infused camera," 2 May 2018 Four concrete hollow cylinders — each 18 feet long and 9 feet in diameter and perforated with a constellation of small apertures emitting patterns of light inside the tube — are arranged in the landscape in an open cross. Hilarie M. Sheets, New York Times, "Dia Acquires ‘Sun Tunnels,’ Its First Piece of Land Art by a Woman," 7 Mar. 2018 The Cloud-Aerosol Transport System, or CATS, instrument was designed to study the atmosphere using a laser firing through a large aperture door. William Harwood, CBS News, "Space station astronauts take spacewalk to install cameras," 14 June 2018

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

11 Oct 2018

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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

: 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 \

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 \

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).


one that holds something together

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