A diphthong is a sound made by combining two vowels, specifically when it starts as one vowel sound and goes to another, like the oy sound in oil.

Diphthong comes from the Greek word diphthongos which means "having two sounds." Notice the di- for "double." So diphthongs are double vowel sounds in words like chair, fear, or pout. If two vowels in a row are the same, as in boot or beer, then it's not a diphthong. Linguists, scholars who study language, analyze diphthongs, which differ from language to language. Ironically, the word diphthong has no diphthongs.

Definitions of diphthong
  1. noun
    a vowel sound that starts near the articulatory position for one vowel and moves toward the position for another
    see moresee less
    type of:
    vowel, vowel sound
    a speech sound made with the vocal tract open
Word Family