al·ve·o·lar / alˈvēələr/ • adj. of or relating to an alveolus, in particular: ∎  Anat. relating to or denoting the bony ridge that contains the sockets of the upper teeth. ∎  Phonet. (of a consonant) pronounced with the tip of the tongue on or near this ridge (e.g., n, s, t). ∎  Anat. of or relating to an alveolus or the alveoli of the lung.• n. Phonet. an alveolar consonant.

ALVEOLAR [Stress: ‘al-VEE-o-lar’].
1. Relating to either of the bony ridges in the mouth that contain the teeth, but especially in phonetics to the ridge behind the upper teeth (the alveolar ridge), and to any sounds made when the TONGUE touches or comes close to it: for example, the CONSONANTS /t, d/ are alveolar stops, while /s, z/ are alveolar fricatives.

2. A sound made in this way: /d/ is a voiced alveolar. See L-SOUNDS, PALATE, R-SOUNDS, SPEECH.