cf. the scholia to Homer, Iliad 6.298, where the headword occurs without nu ephelkystikon (web address 1); similarly glossed also in the Ambrosian Lexicon.
The headword is third person singular, aorist indicative active, of the verb οἴγνυμι or οἴγω , glossed with the aorist of the more common ἀνοίγνυμι . In Epic, the augmented form is usually ὠϊ- (with diaeresis), although the contracted form is attested at Homer, Iliad 24.457. LSJ entry at web address 2. Other forms of this verb appear at omicroniota 21, omega 11, and omega 38.