Wiktionary
diphthongise
vb. (alternative spelling of diphthongize English)
WordNet
diphthongise
v. change from a simple vowel to a diphthong; "This vowel diphthongized in Germanic" [syn: diphthongize]
Usage examples of "diphthongise".
With a classic twin set and, indeed, pearls and a skirt that yelled Jaeger, her bone structure told me how she'd speak before she even opened her mouth: in the well-projected but curiously diphthongised vowels of the upper crust.