air sac

noun

|Updated on: 28 Apr 2018

Definition of air sac

1 : one of the air-filled spaces in the body of a bird connected with the air passages of the lungs

2 : alveolus 1b

3 : a thin-walled dilation of a trachea occurring in many insects

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Recent Examples of air sac from the Web

Birds are also light because much of their insides are filled with air due to extensive space-filling air sacs which are part of their exceptionally efficient respiratory system.

— steven austad, AL.com, "Dinosaurs in the garden," 14 Apr. 2018
Daniel, a 12-year-old Bornean orangutan, was dealing with a sinus infection that left him with labored breathing, coughing, frequent mucous production and a distended air sac, the Phoenix Zoo said in a media release.

— robert gundran, azcentral, "Phoenix Zoo orangutan plagued by sinus problems gets groundbreaking surgery," 22 Mar. 2018
Influenza can develop into pneumonia, an infection that causes the lungs' air sacs to become inflamed and fill with fluid.

— rachel ohm, USA TODAY, "Flu widespread in 36 states, CDC reports," 29 Dec. 2017
The kiwi chick sticks its bill into an air sac at the top of the egg, and starts to squeak.

— ed yong, The Atlantic, "How to Raise the Rarest Kiwi," 20 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'air sac.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of air sac

circa 1805

in the meaning defined at sense 1

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AIR SAC Defined for Kids

air sac

noun

Definition of air sac for Students

: one of the small pouches in the lungs where oxygen and carbon dioxide are exchanged

Medical Dictionary

air sac

noun

medical Definition of air sac

: alveolus b

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air sac

Definition of air sac

Recent Examples of air sac from the Web

First Known Use of air sac

AIR SAC Defined for Kids

air sac

Definition of air sac for Students

Medical Dictionary

air sac

medical Definition of air sac

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air sac

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air sac

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air sac

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