alveoli

noun pl. alveoli

1. Anat., Zool. a small cavity or hollow, as a cell of a honeycomb, air cell of a lung, tooth socket, etc.
2. the alveolar ridge; teethridge

Origin: L, dim. of alveus, a hollow, cavity < alvus, the belly, womb < IE base *au-lo-s > Gr aulos, flute, Lith aulỹs, beehive