A Compound Vowel
This page is the CodyCross answer for the clue below from Café, Group 1330, Puzzle 3 (Beverage Napkins).
Question is: A Compound Vowel
and the answer is: DIPHTHONG
Word Meaning:
DIPHTHONG — (phonology) A complex vowel sound that begins with the sound of one vowel and ends with the sound of another vowel, in the same syllable.
Definitions from Wiktionary.