Phonetics. The action of rounding the lips while enunciating. Also: the action of enunciating a phoneme (esp. a vowel) with rounded lips; an…

The tendency of speech sounds to become labialized; labial articulation.

The action of making a speech sound labial (labial, adj. 1) in pronunciation or articulation, as a secondary articulatory feature; the fact of a…

The action of obscure, v.; an instance of this.

Phonetics. Articulation (of a vowel) with the tongue closer to the roof of the mouth; an instance of this. Cf. raise, v.1 19g.

the action or process of reducing or eliminating rounding (rounding, n.3 5b).

Linguistics. The weakening or obscuring of a vowel; the replacement of one speech sound by another which requires less muscular effort to…

The action of delabializing.

= r-colouring n.

Phonetics. The alteration of a vowel sound so as to be produced in a more central (central, adj. 7) position. Cf. centralized, adj. 3.

the enunciation of a vowel with the speech organs relaxed (cf. lax, adj. 5c).