R-labialization is a process occurring in certain dialects of the English language, particularly some varieties of Cockney, in which the /r/ phoneme is realized as a labiodental approximant [ʋ] in contrast to an alveolar approximant [ɹ]. To English speakers who are not used to [ʋ], this sounds nearly indistinguishable from /w/.
Use of labiodental /r/ is commonly stigmatized by prescriptivists. Regardless, the consonant [ʋ] is used in a variety of other languages and is increasing in many accents of British English. Most speakers doing so are from the southeastern part of the country, particularly in London. It is also occasionally heard in some speakers of Boston and New York City English though more often in an exaggerated parody of these dialects, as famously portrayed by the Looney Tunes character Elmer Fudd.
R-labialization leads to pronunciations such as the following:
- red - [ʋɛd]
- ring - [ʋɪŋ]
- rabbit - [ˈʋæbɪt]
- merry Christmas - [mɛʋi ˈkʋɪsmɪs]
However, replacement of /r/ by some kind of labial approximant may also occur as symptom of a speech defect, called rhotacism or, more precisely, derhotacization.