[ ap-er-cher ]
/ ˈæp ər tʃər /
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.
- apert's syndrome,
- apert-crouzon syndrome,
- aperture card,
- aperture priority,
- aperture ratio,
- aperture synthesis,
Origin of aperture
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
/ (ˈæpətʃə) /
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 openingSee also relative aperture
Word Origin for aperture
C15: from Late Latin apertūra opening, from Latin aperīre to open
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
early 15c., from Latin apertura "an opening," from apertus, past participle of aperire "to open" (see overt).
Online Etymology Dictionary, © 2010 Douglas Harper
[ ăp′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.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.