MONOPHTHONG Meaning of MONOPHTHONG in English transcription, транскрипция: [ ˈmɔnəfθɔŋ ]n. Phonet. a single vowel sound. øømonophthongal adj. [Gk monophthoggos (as MONO-, phthoggos sound)] English main colloquial, spoken dictionary. Английский основной разговорный словарь. 2012