ναετήρ
From LSJ
εἰς πέλαγος σπέρµα βαλεῖν καὶ γράµµατα γράψαι ἀµφότερος µόχθος τε κενὸς καὶ πρᾶξις ἄκαρπος → throwing seeds and writing letters at sea are both a vain and fruitless endeavor
English (LSJ)
ῆρος, ὁ, = sq., AP7.409 (Antip. Thess.), D.P.455, etc.
Greek (Liddell-Scott)
ναετήρ: -ῆρος, ὁ, = τῷ ἑπομ., Χριστοδ. Ἔκφρ. 116, Ἀνθ. Π. 7. 409, κτλ.