ἐκκολούω

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

Source

Spanish (DGE)

impedir, hacer imposible en v. pas. οὐδὲν οὕτως ἐκκεκολοῦσθαι τὸ βάθος Gal.9.230.