Linguistics term for a complex vowel sound that begins with one vowel and glides into another within the same syllable. Often contrasted with 二重母音.
See also: 二重母音
The 'i' in English 'time' is a diphthong.
Formed from 重 in the sense “compound” or “multiple” and 母音 “vowel,” in contrast with 単母音 “monophthong.”