LSJ
οῦ, ὁ, watcher, scout, Sch. rec. A. Th. 36.
superintendent of taxes, ἐ. ἱερᾶς πύλης (at Elephantine in Egypt) Ostr. 144 (ii AD), cf. 1020, al. ; νομῶν BGU 478.4 (ii AD), Arch.Pap. 4.143 (ii AD) ; πλοίων POxy. 2116.1 (iii AD).
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
ὁ, der Beobachter, Schol. Aesch. Spt. 36 u. Sp.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)