Pronunciation: (vou'ul),[key] —n. 1. Phonet. a. (in English articulation) a speech sound produced without occluding, diverting, or obstructing the flow of air from the lungs (opposed to consonant).
b. (in a syllable) the sound of greatest sonority, as i in grill. Cf. consonant (def. 1b).
c. (in linguistic function) a concept empirically determined as a phonological element in structural contrast with consonant, as the (ē) of be (bē), we (wē), and yeast (yēst).
2. a letter representing or usually representing a vowel, as, in English, a, e, i, o, u, and sometimes w and y.