o-grade

o-grade (uncountable)

1. (Indo-European linguistics) In Proto-Indo-European linguistics, a term used to describe 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”).

• e-grade
• zero-grade

• dog ear, dog-ear, dogear, goader