ˈäˌplau̇t, ˈaˌbl- noun
( -s )
Etymology: German, from ab off, away from, down from (from Old High German aba ) + laut sound, from Middle High German lūt; akin to Old English hlūd loud — more at of , loud
: a systematic variation of vowels in the same root or affix or in related roots or affixes in the Indo-European languages usually paralleled by differences in use or meaning (as sing, sang, sung, song; Gk petomai “I fly”, potē “flight”, ptesthai “to fly”, pōtaomai “I fly around”; -es- in assumed IE genesa, L genera “kinds”, -os in assumed IE genos, L genus “kind”) : a similar variation in any language or language family — called also apophony, gradation