The headword appears to be the accusative plural (presumably extracted from somewhere -- perhaps Herodotus 9.98.2) of the feminine noun a)poba/qra, a disembarking ladder or gangway; see LSJ s.v. However, the glossing seems better (though even so, imperfectly) suited to the neuter plural a)po/baqra, defined in LSJ as 'sacrifices on disembarkation'. In any event C. Theodoridis in his Photius edition, vol.II p.XCIX, revives Dindorf's suggestion of a connection with an Aristophanic scholion (on ta\ la/sana in Peace 893) which also features under beta 325 and lambda 133.