triphthong
noun /ˈtrɪfθɒŋ/, /ˈtrɪpθɒŋ/
/ˈtrɪfθɔːŋ/, /ˈtrɪpθɔːŋ/
(phonetics)- a combination of three vowel sounds or vowel letters, for example the sounds /aɪə/ in fire /faɪə(r)/ compare diphthong, monophthongWord Originmid 16th cent.: from French triphtongue, from tri- ‘three’, on the pattern of diphthong.