Definitions for "Diphthong"
A coalition or union of two vowel sounds pronounced in one syllable; as, ou in out, oi in noise; -- called a proper diphthong.
A vowel digraph; a union of two vowels in the same syllable, only one of them being sounded; as, ai in rain, eo in people; -- called an improper diphthong.
To form or pronounce as a diphthong; diphthongize.
Keywords:  slurring, letters, two
The slurring of two letters. (i.e., oi, oy, ou, ow)