ὀπτήρ
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)
ῆρος, ὁ, (ὄψ)
A one who looks or spies, spy, scout, Od. 14.261, A.Supp.185, S.Aj.29. II one who has seen, Id.Ichn.77 ; eye-witness, Antipho 5.27, X.Cyr.4.5.17.
German (Pape)
[Seite 363] ῆρος, ὁ, der nach Etwas sieht, der Späher; ὀπτῆρας δὲ κατὰ σκοπιὰς ὤτρυνα νέεσθαι, Od. 14, 261. 17, 430; Aesch. Suppl. 182; Soph. Ai, 29; Xen. Cyr. 5, 4, 17 u. Sp.