In linguistics, synaeresis (/sɪˈnɛrəsɪs/; also spelled syneresis) is a phonological process of sound change in which two adjacent vowels within a word are combined into a single syllable.
When realized in a careful reading style, each particular word is associated with this single, standard phonetic form.
[2] However, each word also possesses multiple non-standard or reduced phonetic forms which are produced in a greater range of contexts.
For example, the French word louer, which means ‘to praise,’ is typically pronounced as [lwe] according to transcriptions using the International Phonetic Alphabet.
In this example, the standard pronunciation uses the process of synaeresis to compress both of the original vowel sounds into one syllable.
[12] These forms of the word include [lue] according to IPA transcriptions, in which the two vowels are pronounced separately using the process of diaeresis.
[13] In Ancient Greek, synaeresis[n 1] is the merging and pronunciation of two separate vowels as a diphthong (e.g. α + ι → αι /ai̮/) or a long vowel (e.g. ο + ο → ου /ο:/); a characteristic example of this is the conjugation class or classes of contracted verbs (Ancient Greek: συνῃρημένα – or περισπώμενα – ῥήματα).