alveolus

American  

[al-vee-uh-luhs] / ælˈvi ə ləs /

noun

plural

alveoli

1. a little cavity, pit, or cell, as a cell of a honeycomb.

2. an air cell of the lungs, formed by the terminal dilation of tiny air passageways.

3. one of the terminal secretory units of a racemose gland.

4. the socket within the jawbone in which the root or roots of a tooth are set.

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alveolus British  

/ ælˈvɪələs /

noun

1. any small pit, cavity, or saclike dilation, such as a honeycomb cell

2. any of the sockets in which the roots of the teeth are embedded

3. any of the tiny air sacs in the lungs at the end of the bronchioles, through which oxygen is taken into the blood

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alveolus Scientific  

/ ăl-vē′ə-ləs /

plural

alveoli

1. Any of the tiny air-filled sacs arranged in clusters in the lungs, in which the exchange of oxygen and carbon dioxide takes place.

2. Also called air sac

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Etymology

Origin of alveolus

1700–10; < Latin, equivalent to alve ( us ) concave vessel + -olus -ole ¹

Example Sentences

In one example, six nests were stacked within a single alveolus, arranged one inside another like Russian dolls.

From Science Daily • Apr. 3, 2026

Figure 30.10 shows a human alveolus, which is part of the respiratory system.

From Textbooks • Jun. 9, 2022

If you were travelling in a miniaturized ship through the respiratory system, from the pharynx to an alveolus, which structures would you pass along the way, and in what order?

From Textbooks • Jun. 9, 2022

A focus-stacked picture of a tiny, 3D-printed alveolus, or artificial lung.

From Science Magazine • Dec. 16, 2019

The first premolar is not preserved, but its alveolus indicates that it was a single-rooted tooth, placed behind the canine after the intervention of a very short diastema.

From On The Affinities of Leptarctus primus of Leidy American Museum of Natural History, Vol. VI, Article VIII, pp. 229-331. by Wortman, Jacob Lawson