LSJ
οῦ, ὁ, spectator, ἐργάται τῶν καλῶν καὶ θ. Phld. Oec. p. 63J., cf. Hsch. s.v. θεωρούς.
overseer, director, Sch. Oppian. H. 3.257.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
ὁ, Erkl. von θεωρός, Hesych.; K.S.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)