transitive. To make less distinct in quality of sound; (Phonetics) to articulate (a vowel) in a more centralized position.

Phonetics. transitive. To modify (a vowel) by articulating with the tongue further from the roof of the mouth. Cf. raise, v.1 19g.

transitive. To articulate (a speech sound, now esp. a consonant) with rounding or complete or partial closure of the lips as a secondary…

In various spec. uses. transitive. Linguistics. To articulate (a speech sound) in a way requiring less muscular effort; esp. to form (a vowel) in…

transitive. Phonetics. To enunciate (a sound, esp. a vowel) with the lips formed into a round shape. Cf. labialize, v.

transitive. Phonetics. To modify (a vowel) by articulating with the tongue closer to the roof of the mouth. Cf. raising, n.2 1e.

transitive. To make (something) no longer round. In later use spec. (in Phonetics): to reduce or eliminate the rounding of the lips when…

transitive. To deprive of its labial character.

transitive. To make tense; to stretch tight; spec. of vowel sounds (cf. tense, adj. 1c). Also reflexive and with up.