What is another word for diphthong?
Pronunciation: [dˈɪfθɒŋ] (IPA) 
A diphthong is a type of phoneme that consists of two vowel sounds pronounced together in a single syllable. Synonyms for the word diphthong include compound vowel, gliding vowel, vowel cluster, and double vowel. A compound vowel is formed when two vowels are uttered together, but each retains its separate sound, as in the vowel pair "ai" in "sail." A gliding vowel is a vowel sound produced by the transition from one vowel to another, as in the "oi" sound in "boy." A vowel cluster refers to a group of consecutive vowel sounds, like in the word "queue." A double vowel is simply two vowels pronounced consecutively in a single syllable, as in the word "boat".
