an opening, as a hole, slit, crack, gap, etc.
Also called aperture stop. Optics. an opening, usually circular, that limits the quantity of light that can enter an optical instrument.
Contemporary Examples

His book of essays, Photography After Frank , was recently published by aperture.
Hai Bo and China’s Photography Boom Philip Gefter January 19, 2011

Its 8-megapixel camera, inclusive of true-tone and dual-LED f/2.2 aperture flashes, features optical image stabilization.
Why Every Home Needs a Drone This Holiday Charlie Gilbert December 7, 2014

But as this image shows, the nails actually went through an aperture in the wrists.
10 Reasons the Resurrection Really Happened Jeffrey Hart April 9, 2009

His book of essays, Photography After Frank, was recently published by aperture.
Pulp Fictions Philip Gefter September 9, 2009

“Administration officials favorite phrase these days is that, ‘you have to widen the aperture,’” says Bockenfeld.
Obama To Cut Middle East Democracy Programs Jamie Dettmer January 1, 2014

Historical Examples

She held a lamp behind the folds of her skirt, and after she had entered his chamber the aperture closed noiselessly behind her.
The Hill of Venus Nathan Gallizier

Then I stops the aperture below, by putting the chest agin it.
Life And Adventures Of Martin Chuzzlewit Charles Dickens

In each side make an aperture two inches square that can be opened or closed at will.
Overland through Asia; Pictures of Siberian, Chinese, and Tartar Life Thomas Wallace Knox

The transom was open, leaving an aperture of about three inches.
Frank Merriwell’s Pursuit Burt L. Standish

aperture of entry (Mauser), just external to the centre of the right eyebrow; exit, above the centre of the right zygoma.
Surgical Experiences in South Africa, 1899-1900 George Henry Makins

a hole, gap, crack, slit, or other opening

a usually circular and often variable opening in an optical instrument or device that controls the quantity of radiation entering or leaving it
the diameter of such an opening See also relative aperture


early 15c., from Latin apertura “an opening,” from apertus, past participle of aperire “to open” (see overt).

aperture ap·er·ture (āp’ər-chər)

An opening, such as a hole, gap, or slit.

A usually adjustable opening in an optical instrument, such as a microscope, a camera, or a telescope, that limits the amount of light passing through a lens or onto a mirror.

The diameter of such an opening.

The diameter of the objective of a telescope or microscope.

ap’er·tur’al adj.


Read Also:

  • Aperture card

    a punched-card mounting for microfilmed pages.

  • Aperture mask

    . a perforated metal plate situated behind the faceplate of a color television picture tube and having holes aligned to insure that each of three electron beams strikes only its corresponding red, green, or blue phosphor dot. noun (television) a perforated metal sheet mounted close to the phosphor-dotted screen in some colour television tubes. The […]

  • Aperture-priority

    of or relating to a semiautomatic exposure system in which the photographer presets the aperture and the camera selects the shutter speed.

  • Aperture ratio


Disclaimer: Aperture definition / meaning should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. All content on this website is for informational purposes only.