umlaut Noun An assimilatory process whereby a vowel is pronounced more like a following vocoid that is separated by one or more consonants.
umlaut Noun The 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 "lūsi" > Old English "līs(i)" > Modern English lice).
umlaut Noun A vowel so assimilated.
umlaut Noun The diacritical mark ( ¨ ) placed over a vowel to indicate such assimilation.