Ablaut
Pronunciation : Ab"laut
Part of Speech : n.
Etymology : [Ger., off-sound; ab off + laut sound.] (Philol.)
Definition : Defn: 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. Earle.
Source : Webster's Unabridged Dictionary, 1913