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
securely, firmly: P. and V. βεβαίως, ἀσφαλῶς.
obstinately: Ar. and P. ἀυθάδως, P. σκληρῶς.