Definition of diaereses:
(n) :
(linguistics, prosody) (orthography) The diacritical mark consisting of two dots (¨) placed over a letter (especially the second of two consecutive vowels) to indicate that it is sounded separately, usually as a distinct syllable.
(n) :
(linguistics, prosody) A separation of one syllable (especially a vowel which is a diphthong, that is, beginning with one sound and ending with another) into two distinct syllables; distraction.
(n) :
(linguistics, prosody) An occurrence of separate vowel sounds in adjacent syllables without an intervening consonant; a hiatus.
(n) :
(prosody) A natural break in rhythm when a word ends at the end of a metrical foot in a line of verse.
(n) :
(figurative, rare) A division, a separation.
(n) :
(surgery, archaic) An act of separating body parts or tissues which are normally together.