Triphthong

In phonetics, a triphthong (UK: /ˈtrɪfθɒŋ, ˈtrɪpθɒŋ/ TRIF-thong, TRIP-thong, US: /-θɔːŋ/ -⁠thawng) (from Greek τρίφθογγος, "triphthongos", literally "with three sounds," or "with three tones") is a monosyllabic vowel combination involving a quick but smooth movement of the articulator from one vowel quality to another that passes over a third. While "pure" vowels, or monophthongs, are said to have one target articulator position, diphthongs have two and triphthongs three.

Triphthongs are not to be confused with disyllabic sequences of a diphthong followed by a monophthong, as in German Feuer [ˈfɔʏɐ] 'fire', where the final vowel is longer than those found in triphthongs.