synerèse

Synerèse, or synérèse, is a phonological and prosodic process in which two adjacent vowels are pronounced as a single syllable. The result is a reduction in the syllable count of a word or phrase containing the vowel sequence. The term is used in historical linguistics, in the study of Romance languages, and in the analysis of verse, where it relates to meter. It is often described as the opposite of hiatus, which preserves two separate syllables for a vowel sequence.

The realization and acceptability of synerèse vary by language and dialect, and by historical period. In some languages or styles, syllable merger occurs regularly in certain vowel combinations; in others it appears only in specific poetic contexts or informal speech. Across word boundaries, synerèse can occur in fluent speech or in prepared verse, while in other situations the vowels remain distinct, resulting in hiatus. In poetry, synerèse is a tool for shaping meter and rhythm, whereas hiatus can be used to create a deliberate break or to accommodate metrical requirements.

Etymology traces the term to Greek roots, combining a prefix meaning “together” with a element meaning “taking away” or “merging,” to express the idea of two vowels being joined into one sound.

See also: vowel reduction, hiatus, elision (prosody).