Definitions
1.NounAn assimilatory process whereby a vowel is pronounced more like a following vocoid that is separated by one or more consonants.
2.NounThe umlaut process (as above) that occurred historically in Germanic languages whereby back vowels became front vowels when followed by syllable containing a front vocoid (e.g. Germanic lūsiz > Old English lȳs(i) > Modern English lice).
3.NounA vowel so assimilated.
4.NounThe diacritical mark ( ¨ ) placed over a vowel when it indicates a (rounded) front vowel
5.NounSynonym of diaeresis.""Naïve" takes an umlaut because it is pronounced as two syllables."
6.VerbTo place an umlaut over (a vowel).
7.VerbTo modify (a word) so that an umlaut is required in it."an umlauting vowel"