(in English articulation) a speech sound produced without occluding, diverting, or obstructing the flow of air from the lungs (opposed to consonant).
(in a syllable) the sound of greatest sonority, as i in grill. Cf.consonant(def. 1b).
(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).
a letter representing or usually representing a vowel, as, in English, a, e, i, o, u, and sometimes w and y.