A small or narrow opening, gap, slit, or hole. / (optics) A hole which restricts the diameter of the lightpath through one plane in an optical system.

plural of aperture

Having an aperture (or a specified type of aperture).

(palynology, of a pollen grain) Having one or more apertures

Relating to an aperture.

(palynology) Section of exine forming the base of an aperture

Alternative form of aperture priority

(photography, often used attributively) A setting in many professional-grade and advanced-amateur-grade cameras which allows a photographer to manually set the aperture setting of an exposure while the camera then automatically selects the correct shutter speed for that exposure.

plural of aperture membrane

(anatomy) The anterior opening of the nasal cavities in the skull.