ablaut
/ˈæblaʊt/noun
mass noun
- alternation in the vowels of related word forms, especially in Germanic strong verbs (e.g. in sing, sang, sung)（相关词形中的）元音交替（尤指源自日耳曼语系的强变化动词,如sing, sang, sung）。
词源
mid 19th cent.: from German, from ab 'off' + Laut 'sound'.