Synizesis

Synizesis (/ˌsɪnəˈziːsɪs/) is a sound change (metaplasm) in which two originally syllabic vowels (hiatus) are pronounced instead as a single syllable. In poetry, the vowel contraction would often be necessitated by the metrical requirements of the poetic form. Synizesis is also understood to occur as a natural product in the evolution of a language over time.

A tie may be used to represent this pronunciation: dē͡hinc (i.e., deinc).