Definition of diphthong in English:

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Pronunciation: /ˈdɪfθɒŋ/
Pronunciation: /ˈdɪpθɒŋ/


1A sound formed by the combination of two vowels in a single syllable, in which the sound begins as one vowel and moves towards another (as in coin, loud, and side). Often contrasted with monophthong, triphthong.
Example sentences
  • The language has a musical quality and employs a great number of diphthongs and other vowel combinations.
  • Density is thus largely a function of word stock and reflects at this stage in Coolidge's work an affinity for monosyllabic words, particularly those that couple long vowels or diphthongs with consonant blends.
  • Most Modern English vowels are diphthongs, so obeying the ‘one sound, one letter’ rule demands either pairing of vowel letters or replacing all our current vowel sounds with the fewer pure sounds, as in Italian and Spanish.
1.1A digraph representing the sound of a diphthong or single vowel (as in feat).
Example sentences
  • The Pali alphabet used for written Burmese is made up of eight vowels, three diphthongs, 32 consonants, and several tones.
  • However, all subsequent authors except Meek have used the diphthong, so Archaeocyathus is now treated as a justified emendation of Billings' original spelling.
1.2A compound vowel character; a ligature (such as æ).


For a discussion of the pronunciation of diphthong, see diphtheria (usage).



Pronunciation: /dɪpˈθɒŋɡ(ə)l/
Pronunciation: /dɪfˈθɒŋɡl/
Example sentences
  • These three models all crucially contribute to my explanation of variation and changes currently observed in the diphthongal system of Seoul Korean.
  • They are represented by two letters, one indicating the start of the diphthongal movement, the other indicating its end or general direction.
  • Otherwise the dialect is solidly Midland, and aside from Germanisms bears a close affinity with the Philadelphia area, such as in its use of diphthongal long O and long A.


Late Middle English: from French diphtongue, via late Latin from Greek diphthongos, from di- 'twice' + phthongos 'voice, sound'.

For editors and proofreaders

Line breaks: diph|thong

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