Meaning

noun a vowel sound that starts near the articulatory position for one vowel and moves toward the position for another

originPIE word *dwóh₁ Etymology tree Proto-Indo-European *dwóh₁ Proto-Indo-European *dwi- Proto-Hellenic *dwi- Ancient Greek δι- (di-) Ancient Greek φθέγγομαι (phthéngomai) Ancient Greek φθόγγος (phthóngos) Ancient Greek δῐ́φθογγος (dĭ́phthongos)der. Latin diphthongusbor. French diphtongueder. English diphthong From French diphtongue, from Late Latin diphthongus, from Ancient Greek δίφθογγος…

Etymology from Wiktionary, CC BY-SA 3.0