UMLAUTED
Verb
umlauted
simple past tense and past participle of umlaut
Adjective
umlauted (not comparable)
Modified by the addition of an umlaut.
Source: Wiktionary
Um"laut*ed, a. (Philol.)
Definition: Having the umlaut; as, umlauted vowels.
There is so natural connection between umlauted forms and plurality.
Earle.
UMLAUT
Um"laut, n. Etym: [G., from um about + laut sound.] (Philol.)
Definition: The euphonic modification of a root vowel sound by the
influence of a, u, or especially i, in the syllable which formerly
followed.
Note: It is peculiar to the Teutonic languages, and was common in
Anglo-Saxon. In German the umlauted vowels resulting from a, o, u,
followed by old i, are written ä, ö, ü, or ae, oe, ue; as, männer or
maenner, men, from mann, man. Examples of forms resulting from umlaut
in English are geese pl. of goose, men pl. of man, etc.
Source: Webster’s Unabridged Dictionary 1913 Edition