Lewis & Short

cătascŏpus, i, m., = κατάσκοπος (exploring, spying (cătascŏpĭum, ii, n., Gell. 10, 25 fin.), = κατασκόπιον, a lookoutship, a spy-ship, a vessel sent out to reconnoitre (pure Lat. navigium speculatorium), Auct. B. Afr. 26; cf. Isid. Orig. 19, 1, 18.