ALVEOLUS

noun (plural alveoli) Etymology: New Latin, from Latin, diminutive of alveus cavity, hollow, from alvus belly, beehive; akin to Lithuanian aulys beehive, Greek aulos tube, flute Date: circa 1706 a small cavity or pit: as, a socket in the jaw for a tooth, a small air-containing compartment of the lungs in which the bronchioles terminate and from which respiratory gases are exchanged with the pulmonary capillaries, an acinus of a compound gland, a cell of a honeycomb, teethridge