Diæresis

Diæresis (Gr., from diaireō, 'I divide'), a term used in Grammar to signify the resolution of a diphthong, or of a contracted syllable, into two syllables; as Lat. auræ into aurai. The name is also given to the mark " placed above a vowel letter to indicate that it is to be independently pronounced, and not in conjunction with a preceding vowel; as in the above example, or in the word aërial. See UMLAUT.