The word defined here is epic, occurring in Homer, Iliad 13.707 and Odyssey 18.375; also in later epic. It is attested only in the accusative case, singular (as here; Herodian Gr. 3.2, p.758, posits the nominative ὦλξ ) and plural.
The gloss is a more commonplace word for furrow; cf. alpha 4433.