noun \ˈä-blau̇t, ˈa-; ˈäp-ˌlau̇t\
Definition of ABLAUT
: a systematic variation of vowels in the same root or affix or in related roots or affixes especially in the Indo-European languages that is usually paralleled by differences in use or meaning (as in sing, sang, sung, song)
Origin of ABLAUT
German, from ab away from + Laut sound
First Known Use: 1849
Reproduced with thanks to the Merriam-Webster Dictionary.