rückumlaut
noun
rück·umlaut
ˈrᵫk+ˌ-
: the absence of umlaut of the stem vowel in the past tense and past participle of some Germanic weak verbs as a result of the loss of i in the following syllable before the umlaut period
Word History
Etymology
German literally, back umlaut, from rück- (from zurück back, backward, from Middle High German ze rücke, from ze to—from Old High German zi—+ rücke back, from Old High German hrukki) + umlaut