epenthesis

credit: LOLphonology at facebook

Jack Windsor Lewis, a purist in matters terminological (cf. his comments on 'rhotic' or 'RP'), in his blog # 299 of the 21st of September writes on epenthetic wyns, i.e. the unetymological, paralinguistic insertion of a w-like glide between the abutting vowels in go on or co-operate (and many other similar combinations) so that the latter is pronounced [kə(ʊ)^wɒpəreɪt] (or even as a very emphatic [kə(ʊw)ɒpəreɪt]) to use a very broad phonetic transcription. As an aside he rejects the application of the term intrusive because it "[...] might be misconstrued as indicating a value judgment." Among phoneticians and linguists chances are very slim that they will use intrusive r as a depreciatory term. Rather, they seem to use it simply as a descriptive designation (some of them to deny the existence of such an epenthetic wyn). However, intrusive describes the property of intruding without having been invited or being welcome (OED 3: s.v. intrusive). Weighing all this up epenthetic is without doubt the more neutral term.