Answer: diereses

AnswerCrossword Clue
DIERESESMarks over vowels
DIERESESDiphthong dividers
DIERESESUmlauts' kin (Var.)
dieresessign (¨) placed over the second of two vowels, indicating it is pronounced separately, as in Noël
dieresesDIERESIS, the separation of two vowels into two syllables