Definition of alveolus in English:


Pronunciation: /ˌalvɪˈəʊləs//alˈvɪələs/


  • 1Any of the many tiny air sacs of the lungs which allow for rapid gaseous exchange.

    • ‘He found a major cause of bronchial asthma and many other chronic diseases to be a deficiency of carbon dioxide in the alveolus of our lungs.’
    • ‘Scientists also suspect that air pollutants might dampen the growth of alveoli, tiny air sacs in the lungs.’
    • ‘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.’
    • ‘Holes in the lungs occur as the alveoli air sacs break down.’
    • ‘Many alveoli in the functioning lung can remain at low volume for extended periods.’
    1. 1.1An acinus (sac-like cavity) in a gland.
  • 2The bony socket for the root of a tooth.

    • ‘No preserved teeth or alveoli can be observed in the premaxilla and dentary bones.’
    • ‘These problems can be fixed by grafting bone matter onto the alveolus.’
    • ‘Only a few, fragmentary teeth are preserved, and judging by the fragments and the size of alveoli, the teeth were gracile.’
    • ‘The tooth row is present throughout the entire preserved length of the jaw and possesses 16 teeth and empty alveoli.’
    • ‘The tooth is two-rooted, with each root housed in its own alveolus.’


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