labio-velar (adj./n.)

A term used in the PHONETIC classification of speech sounds on the basis of their PLACE OF ARTICULATION: it refers to a sound made at the velum with the simultaneous accompaniment of lip-ROUNDING. A ‘labio-velar SEMI-VOWEL’ occurs in English as /w/, e.g. well, wasp; some ACCENTS preserve a VOICELESS PHONEME  for words written with wh, and thus CONTRAST such pairs as Wales and whales.