alveolus

al·ve·o·lus

noun \al-ˈvē-ə-ləs\

plural al·ve·o·li \-ˌlī, -(ˌ)lē\

Definition of ALVEOLUS

: 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

Illustration of ALVEOLUS