o-grade
noun1
Indo European studies In Proto-Indo-European linguistics, an ablaut form of a Proto-Indo-European root, characterised by the presence of the */o/ vowel phoneme in place of */e/.
- Ancient Greek γόνος (gónos) is a reflex of *ǵónh₁os (“race”), which is itself an o-grade derivative of the root *ǵenh₁- (“to beget; to produce, bear”).
- A considerable number of derived nominals, especially thematic nouns, also exhibited o-grade roots.2006, Donald Ringe, From Proto-Indo-European to Proto-Germanic (A Linguistic History of English; 1), Oxford: Oxford University Press, →ISBN, page 12: