diphthongization
noun/ˌdɪfθɒŋaɪˈzeɪʃn/, /ˌdɪpθɒŋaɪˈzeɪʃn/
/ˌdɪfθɔːŋəˈzeɪʃn/, /ˌdɪpθɔːŋəˈzeɪʃn/
(British English also diphthongisation)
[uncountable] (phonetics)- the act of changing a vowel into a diphthong
Check pronunciation:
diphthongization