SG Heritage Dictionary

Diphthong [Noun] Webster's Dictionary 1913

1. A coalition or union of two vowel sounds pronounced in one syllable; as, ou in out, oi in noise; -- called a proper diphthong.

2. 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.

Diphthong [Verb transitive] Webster's Dictionary 1913

To form or pronounce as a diphthong; diphthongize.

Diphthongal [Adjective] Webster's Dictionary 1828

Belonging to a diphthong; consisting of two vowel sounds pronounced in one syllable.

Diphthongal [Adjective] Webster's Dictionary 1913

Relating or belonging to a diphthong; having the nature of a diphthong.

Diphthongalize [Verb transitive] Webster's Dictionary 1913

To make into a diphthong; to pronounce as a diphthong.

Diphthongation [Noun] Webster's Dictionary 1913

See Diphthongization.

Diphthongic [Adjective] Webster's Dictionary 1913

Of the nature of diphthong; diphthongal.

Diphthongization [Noun] Webster's Dictionary 1913

The act of changing into a diphthong.

Diphthongize [Verb transitive and intransitive] Webster's Dictionary 1913

To change into a diphthong, as by affixing another vowel to a simple vowel.