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alveolus Line breaks: al¦veo|lus
Pronunciation: /ˌalvɪˈəʊləs/

Definition of alveolus in English:

noun (plural alveoli ˌalvɪˈəʊlʌɪalˈvɪəliː)

chiefly Anatomy
1A small cavity, pit, or hollow, in particular:
Example sentences
  • Recent studies have shown that it may have a critical role in lung growth, affecting new formation of both alveoli and pulmonary blood vessels.
  • The main wall of the duct between alveoli contains smooth muscle.
  • We did not find differences in the content of elastic fibers in the distal alveoli between patients with asthma and control subjects.
1.1Any of the many tiny air sacs of the lungs which allow for rapid gaseous exchange.
Example sentences
  • Scientists also suspect that air pollutants might dampen the growth of alveoli, tiny air sacs in the lungs.
  • Holes in the lungs occur as the alveoli air sacs break down.
  • As altitude increases above sea level, atmospheric pressure drops with a parallel decrease in the amount of oxygen available at the blood/air interface in the lung alveolus.
1.2The bony socket for the root of a tooth.
Example sentences
  • No preserved teeth or alveoli can be observed in the premaxilla and dentary bones.
  • The tooth row is present throughout the entire preserved length of the jaw and possesses 16 teeth and empty alveoli.
  • Only a few, fragmentary teeth are preserved, and judging by the fragments and the size of alveoli, the teeth were gracile.
1.3An acinus (sac-like cavity) in a gland.
Example sentences
  • The most anterior alveolus is the smallest, but the exact size of the second and third cannot be determined owing to breakage of their walls.


Pronunciation: /alvɪˈəʊlət/
Example sentences
  • The Siddall group addressed the molecular phylogeny of three, very similar, alveolate genera.
  • Several workers have suggested that the entire alveolate clade is derived from a photosynthetic ancestor.
  • One of them corresponded to an alveolate sequence belonging to the recently described marine.


Late 17th century: from Latin, 'small cavity', diminutive of alveus.

Words that rhyme with alveolus

Aeolus, bolas, bolus, gladiolus, holus-bolus, solus, toeless
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