air sac

noun

1

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

2

: alveolus sense 1b

3

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

Examples of air sac in a Sentence

Recent Examples on the Web

Chronic inflammation will eventually lead to scarring of the tiny air sacs, as well as the thickening and narrowing of the airways. —Lana Barhum, Verywell Health, 26 Feb. 2025

Pneumonia is an infection in the air sacs of the lung. —Dr. Marc Siegel Fox News, Fox News, 25 Feb. 2025

Bronchitis can lead to pneumonia, a deeper and far more serious infection of the lungs’ air sacs. —Landon Mion, Fox News, 19 Feb. 2025

Created in 1969 by Stanford engineers Victor Scheinman and Larry Leifer, the arm could extend by inflating several of 28 air sacs sandwiched between seven metal disks. —IEEE Spectrum, 27 Apr. 2011

Word History

First Known Use

circa 1805, in the meaning defined at sense 1

Rhymes for air sac

• aback
• anzac
• attack
• backpack
• backtrack
• bareback
• blackjack
• brownback
• buyback
• callback
• cognac
• comeback

Kids Definition

air sac

noun

1

: one of the air-filled spaces connected with the lungs of a bird

2

: one of the thin-walled microscopic pouches in which gases are exchanged in the lungs

Medical Definition

air sac

noun

: alveolus sense b