diphthongize

 
Pronunciation: /ˈdɪfθɒŋʌɪz, ˈdɪp-/
(also diphthongise)

verb

[with object]
  • change (a vowel) into a diphthong: the short vowel was not lengthened or diphthongized

Derivatives

diphthongization

Pronunciation: /-ˈzeɪʃ(ə)n/
noun