umlaut Linguistics [ 'ʊmlaʊt ]
■ noun
1》 a mark (¨) used over a vowel, especially in German, to indicate a different vowel quality.
2》 the process in Germanic languages by which the quality of a vowel was altered in certain phonetic contexts.
■ verb modify with an umlaut.
Origin
C19: from Ger. Umlaut , from um 'about' + Laut 'sound'.