alveolus

noun

al·​ve·​o·​lus al-ˈvē-ə-ləs 

plural alveoli al-ˈvē-ə-ˌlī 

-(ˌ)lē

1

: a small cavity or pit: such as

a

: a socket in the jaw for a tooth

b

: a small air-containing compartment of the lungs in which the bronchioles terminate and from which respiratory gases are exchanged with the pulmonary capillaries

c

: an acinus of a compound gland

d

: a cell of a honeycomb

2

: alveolar ridge sense 2

Examples of alveolus in a Sentence

Recent Examples on the Web

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

More fluid enters the alveolus. —Avesta Rastan, Discover Magazine, 9 June 2020

But even when a patient is severely ill, some alveoli still function well. —Olivia Carville, Bloomberg.com, 10 May 2020

This could explain how the alveoli fail to oxygenate the blood without the patient noticing the need to gasp for more air. —Fox News, 28 Apr. 2020

These millions of alveoli are so soft, so gentle, that a healthy lung has almost no substance. —oregonlive, 7 Apr. 2020

Word History

Etymology

New Latin, from Latin, diminutive of alveus cavity, hollow, from alvus belly, beehive; akin to Lithuanian aulys beehive, Greek aulos tube, flute

First Known Use

1657, in the meaning defined at sense 1

Kids Definition

alveolus

noun

al·​ve·​o·​lus al-ˈvē-ə-ləs 

plural alveoli -ˌlī 

-(ˌ)lē

: a small cavity or pit

especially : an air cell of the lungs

Medical Definition

alveolus

noun

al·​ve·​o·​lus al-ˈvē-ə-ləs 

plural alveoli -ˌlī  -(ˌ)lē 

: a small cavity or pit: as

a

: a socket in the jaw for a tooth

b

: any of the small thin-walled air-containing compartments of the lung that are typically arranged in saclike clusters into which an alveolar duct terminates and from which respiratory gases are exchanged with the pulmonary capillaries

c

: an acinus of a compound gland

d

: any of the pits in the wall of the stomach into which the glands open