aperture

noun

ap·​er·​ture ˈa-pər-ˌchu̇r 

ˈa-pə-,

-chər,

-ˌtyu̇r,

-ˌtu̇r

1

: an opening or open space : hole

entered the cave through a narrow aperture

2

a

: 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

Synonyms

• hole
• opening
• orifice
• perforation

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

Kyiv's military intelligence agency has extensively used synthetic aperture radar (SAR) satellites to coordinate its long-range drone strikes on Russia, as Newsweek previously reported. —Daniel R. Depetris, Newsweek, 10 Jan. 2025

Sharp shooters with relatively fast aperture, producing clean shots at the wide (main and selfie camera), or 85mm telephoto (3X zoom) focal length. —Ben Sin, Forbes, 3 Jan. 2025

Launching from an Indian rocket, the spacecraft will carry a variety of sensors, some provided by NASA, to study shifts in Earth’s land- and ice-covered surfaces using synthetic aperture radar. —Michael Roston, New York Times, 1 Jan. 2025

The expansion underwent changes in 2014, with a Diller Scofidio + Renfro extension that, in addition to demolishing the American Folk Art Museum next door, added an angular metal canopy to call attention to the Fifty-Third Street entrance, in Taniguchi’s design a subtle aperture. —News Desk, Artforum, 30 Dec. 2024

Word History

Etymology

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

First Known Use

15th century, in the meaning defined at sense 1

Kids Definition

aperture

noun

ap·​er·​ture ˈap-ə(r)-ˌchu̇(ə)r 

-chər

1

: an opening or open space : hole

2

a

: the opening in a camera lens that allows light through

b

: the diameter of the opening in a camera lens

Medical Definition

aperture

noun

ap·​er·​ture ˈap-ə(r)-ˌchu̇(ə)r, -chər, -ˌt(y)u̇(ə)r 

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