Definition of "diaeresis"

(orthography) A diacritic (◌̈) placed over a vowel letter (especially the second of two consecutive ones) indicating that it is sounded separately, usually forming a distinct syllable, as in the English words naïve, Noël and Brontë, the French haïr and the Dutch ruïne.  examples

(linguistics, prosody) Distraction; the separation of a vowel, often a diphthong, into two distinct syllables.  examples

(prosody) A natural break in rhythm when a word ends at the end of a metrical foot, in a line of verse.  examples

(linguistics, prosody) Hiatus; the occurrence of separate vowel sounds in adjacent syllables without an intervening consonant.  examples