The headword is actually the imperfect indicative active, third person singular, of the verb e)piorke/w (LSJ entry at web address 1) -- and Adler notes Kuster's proposal to emend the gloss to that effect. It is perhaps quoted here (and in ps.-Zonaras 541) from Dionysius of Halicarnassus, Roman Antiquities 5.10.6; but see also e.g. Olympiodorus, Commentaries on Plato's Alcibiades 884; Sozomenus, Ecclesiastical History 4.24.6.
For other occurrences of misinterpretation in verbal forms see e.g. alphaiota 323, delta 1250, epsilon 1849, eta 37, iota 160.