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[al-vee-uh-luh s] /ælˈvi ə ləs/
noun, plural alveoli
[al-vee-uh-lahy] /ælˈvi əˌlaɪ/ (Show IPA)
a little cavity, pit, or cell, as a cell of a honeycomb.
an air cell of the lungs, formed by the terminal dilation of tiny air passageways.
one of the terminal secretory units of a racemose gland.
the socket within the jawbone in which the root or roots of a tooth are set.
Origin of alveolus
1700-10; < Latin, equivalent to alve(us) concave vessel + -olus -ole1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for alveoli


noun (pl) -li (-ˌlaɪ)
any small pit, cavity, or saclike dilation, such as a honeycomb cell
any of the sockets in which the roots of the teeth are embedded
any of the tiny air sacs in the lungs at the end of the bronchioles, through which oxygen is taken into the blood
Word Origin
C18: from Latin: a little hollow, diminutive of alveus
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for alveoli



1706, from Latin alveolus "a tray, trough, basin; bed of a small river," diminutive of alvus "belly, stomach, paunch, bowels; hold of a ship," from PIE *aulo- "hole, cavity" (cf. Greek aulos "tube, pipe," Old Church Slavonic uliji, Lithuanian aulys "beehive" (hollow trunk), Armenian yli "pregnant").

Online Etymology Dictionary, © 2010 Douglas Harper
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alveoli in Medicine

alveolus al·ve·o·lus (āl-vē'ə-ləs)
n. pl. al·ve·o·li (-lī')
A small angular cavity or pit, such as a tooth socket or an air sac.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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alveoli in Science
Plural alveoli (āl-vē'ə-lī')
Any of the tiny air-filled sacs arranged in clusters in the lungs, in which the exchange of oxygen and carbon dioxide takes place. Also called air sac.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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