air sac


noun

a sac containing air.
any of certain cavities in a bird's body connected with the lungs.
a saclike dilation of the wall of a trachea in many insects.

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Origin of air sac

First recorded in 1820–30
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for air sac

British Dictionary definitions for air sac

air sac

noun

any of the membranous air-filled extensions of the lungs of birds, which increase the efficiency of gaseous exchange in the lungs
any of the thin-walled extensions of the tracheae of insects having a similar function
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

Medical definitions for air sac

air sac

n.

A tiny, thin-walled, capillary-rich sac in the lungs where the exchange of oxygen and carbon dioxide takes place.alveolar sac
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for air sac

air sac

An air-filled space in the body of a bird that forms a connection between the lungs and bone cavities and aids in breathing and temperature regulation.
See alveolus.
A saclike enlargement in the trachea of an insect.
A baglike piece of skin or tissue below the jaw of certain animals, such as the bullfrog and orangutan, that can be inflated to increase sound production.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.