D defs.my
Entry 1 sense Webster, 1913

Ablaut

· Ab·laut · IPA /ˈɑbˌlaʊt/
01 n. The substitution of one root vowel for another, thus indicating a corresponding modification of use or meaning; vowel permutation; as, get,…
  1. 1.
    The substitution of one root vowel for another, thus indicating a corresponding modification of use or meaning; vowel permutation; as, get, gat, got; sing, song; hang, hung.(Philol.)