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
col-līmĭtānĕus: (conl-), a, um, adj.,
I bordering upon; with dat.: Phrygia Galatiae, Sol. 40, 9.
collīmĭtānĕus, a, um (cum, limitaneus), limitrophe : Sol. 40, 9 ; Aug. Serm. 46, 27.