umlaut (ŏmˈlout) [key] [Ger., = transformed sound], in inflection, variation of vowels of the type of English man to men. In this instance it is the end product of the effect of a y (long since disappeared) that was present in the plural; the y caused the vowel before the n to be pronounced higher and more forward in the mouth in the plural than in the singular; eventually there was replacement of the vowel in the plural. Other examples are mouse, mice; tooth, teeth; to fall, to fell; doom, deem. Umlaut is also called mutation and inflection. For the variation of sing, sang, see ablaut. Umlaut is also the name for the diacritical symbol placed above a vowel to indicate a sound change in Germanic languages, as in the German Fräulein and the Swedish fröken (see accent).