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

Between the aperture at six o’clock featuring a sliding carousel of seven emojis, the yellow squiggly seconds hand and the nostalgic color scheme, the piece is an instant classic. —Victoria Gomelsky, Robb Report, 17 July 2024

Capella builds and operates synthetic aperture radar satellites that render Earth, even in adverse weather conditions. —Colin Demarest, Axios, 17 July 2024

The aperture ring sits just ahead of the camera mount. —PCMAG, 15 July 2024

Exploring frames is like looking at a scene through various camera lenses while adjusting your angle, aperture, and focus. —Julia Binder michael D. Watkins, Harvard Business Review, 17 Feb. 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