ab·laut 
(äblout′, äp-)
(äblout′, äp-)n.
A vowel change, characteristic of Indo-European languages, that accompanies a change in grammatical function; for example, i, a, u in sing, sang, sung. Also called apophony, gradation.
[German : ab, off (from Middle High German ab, abe, from Old High German aba; see apo- in the Appendix of Indo-European roots) + Laut, sound (from Middle High German lūt, from Old High German hlūt; see kleu- in the Appendix of Indo-European roots).]
- Indo-European root: melit-
- Indo-European root: melə-
- Indo-European root: men-
- Indo-European root: men-
- Indo-European root: men-
- Indo-European root: men-
- Indo-European root: mendh-
- Indo-European root: menegh-
- Indo-European root: mer-
- Indo-European root: merg-
- Indo-European root: meuə-
- Indo-European root: mizdho-
- Indo-European root: mori-
- Indo-European root: mregh-u-
- Indo-European root: mā-
- Indo-European root: mā-
- Indo-European root: māk-
- Indo-European root: māter-
- Indo-European root: mē-
- Indo-European root: mē-
- Indo-European root: mē-
- Indo-European root: mē-
- Indo-European root: mūs-
- Indo-European root: nas-
- Indo-European root: ne