The story
- German · calque ofNullstufe
- English todayzero-grade
From zero + grade, as in gradation (“apophony”). Possibly after German Nullstufe.
Etymology from Wiktionary, CC BY-SA 4.0.
zero-grade
Today it means: In Proto-Indo-European linguistics, an ablaut form of a root characterized by the absence of the basic ablauting vowel phonemes */e/ and */o/. Full definition →
German Nullstufe