Source : Webster's Revised Unabridged Dictionary (1913)

Alveolar \Al"ve*o*lar\, a. (Phon.)
   Articulated with the tip of the tongue pressing against the
   alveolar processes of the upper front teeth.

Alveolar \Al"ve*o*lar\ (?; 277), a. [L. alveolus a small hollow
   or cavity: cf. F. alv['e]olaire.] (Anat.)
   Of, pertaining to, or resembling, alveoli or little cells,
   sacs, or sockets.

   {Alveolar processes}, the processes of the maxillary bones,
      containing the sockets of the teeth.

Source : WordNet®

alveolar
     adj 1: pertaining to the tiny air sacs of the lungs
     2: pertaining to the alveolar ridge; "alveolar consonant"

alveolar
     n : a consonant articulated with the tip of the tongue near the
         gum ridge [syn: {alveolar consonant}, {dental consonant}]