Main Entry:

ab·laut

Pronunciation:

\ˈä-blau̇t, ˈa-; ˈäp-ˌlau̇t\

Function:

noun

Etymology:

German, from ab away from + Laut sound

Date:

1849

: 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)