umlaut
1. um.laut \'u.m-.lau.t, 'u:m-\ n [G, fr. um- around + laut sound] 1a: the
change of a vowel caused by partial assimilation to a succeeding so und;
esp : the fronting or raising of a back or low vowel (as a, o, or u) caused
by an i or j orig. standing the following syllable but usu. lost or altered
1b: a vowel resulting from such partial assimilation 2: a diacritical mark
: placed esp. over a German vowel to indicate u mlaut
2. umlaut vt 1: to produce by umlaut 2: to write or print an umlaut over