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

In addition, damaged air sacs lose their ability to stretch and shrink back. —Kathi Valeii, Verywell Health, 4 July 2024

Her primary focus was on hyaline membrane disease, sometimes called respiratory distress syndrome, in which alveoli — tiny air sacs in the lungs — do not properly inflate. —Matt Schudel, Washington Post, 3 July 2024

Aman Tripathi 12 days ago 0 Science Birds evolved air sacs to pack propulsion punch for soaring flight The discovery of the unique air sac, known as a subpectoral diverticulum, or SPD, happened by accident. —Interesting Engineering, 23 June 2024

The infection causes the air sacs to fill with pus, making breathing hard. —Amanda MacMillan, Health, 3 May 2024

Word History

First Known Use

circa 1805, in the meaning defined at sense 1

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