An Etymological Dictionary of Astronomy and Astrophysics

Phonetics: A → vowel sound produced by a blended sequence of two separate vowels in a single syllable, where the sound begins as one vowel and moves toward another (as in loud, light, and lair).

Etymology (EN): From M.Fr. diphthongue, from L.L. diphthongus, from Gk. diphthongos “having two sounds,” from → di- “double” + phthongos “sound, voice.”

Etymology (PE): Dovâké, from do “two, → di-” + vâké, vâk, → voice.