ἰδιογενής
From LSJ
χαῖρ', ὦ μέγ' ἀχρειόγελως ὅμιλε, ταῖς ἐπίβδαις, τῆς ἡμετέρας σοφίας κριτὴς ἄριστε πάντων → all hail, throng that laughs untimely on the day after the festival, best of all judges of our poetic skill
English (LSJ)
ές,
A mating only with its kind, opp. κοινογενής, Pl.Plt.265e. 2 peculiar in kind, Herm. ap.Stob.1.49.44, Dsc.2.66.