Answer: diphthongs

AnswerCrossword Clue
diphthongsDIPHTHONG, a union of two vowels pronounced in one syllable
diphthongsA compound vowel character; a ligature (such as ยต)
diphthongsA sound formed by the combination of two vowels in a single syllable, in which the sound begins as one vowel and moves toward another (as in coin, loud, and side)
diphthongsA digraph representing the sound of a diphthong or single vowel (as in feat)