polyphthong

Noun

polyphthong (plural polyphthongs)

1. A phoneme that begins with the sound of one vowel or semivowel and transitions through one or more other (semi)vowel sounds.
   • The teacher who uses Pinyin without knowing about such things as the place of the tone symbol in the case of polyphthong finals is merely incompetent but the teacher who supports the student in developing false notions about the language norm by adopting a systematically casual attitude to its...1973, Journal of the Chinese Language Teachers Association, page 65
   • A syllable is short when ending in a short monophthong or in a short polyphthong; a syllable is long when ending in a consonant or in a long monophthong or a long polyphthong.1997, Ilse Lehiste, Jaan Ross, Estonian Prosody: Papers from a Symposium
2. A diaphoneme realized as a multitarget vowel in some but not necessarily all dialects.