Diaeresis (diacritic)
Diaeresis ( dy-ERR-ə-siss, -EER-) is a diacritical mark consisting of two dots (◌̈) that indicates that two adjacent vowel letters are separate syllables – a vowel hiatus (also called a diaeresis) – rather than a digraph or diphthong. It consists of a two dots diacritic placed over a letter, generally a vowel.