συνναυμαχέω
From LSJ
Οὗτος Ἰουστῖνον καὶ Νεοβιγάστην στρατηγοὺς προβαλόμενος, καὶ τὰς Βρεττανίας ἐάσας, περαιοῦται ἅμα τῶν αὐτοῦ ἐπὶ Βονωνίαν → He appointed Justinus and Neovigastes as generals, and leaving Britain, crossed with his forces to Bononia.(Olympiodorus/Photius)
English (LSJ)
A engage in a sea-fight along with, τισι Hdt.8.44, cf. Ar.Ra.702 (troch.), Th.1.73, IG12.108.41.