διαναυμαχεῖν
From LSJ
διὸ καὶ μεταλάττουσι τὴν φυσικὴν χρῆσιν εἰς τὴν παρὰ φύσιν αἱ δοκοῦσαι παρθένοι τῶν εἰδώλων → therefore those professing to be virgins of the idols even change the natural use into the unnatural (Origen, commentary on Romans 1:26)
Greek > English (Woodhouse Verbs Reversed)
(see also διαναυμαχέω): engage in a sea fight, fight a sea battle
Lexicon Thucydideum
navali proelio decertare, to fight a naval battle, 7.60.2. 8.27.1. 8.78.1 [ubi Vat. where Vatican manuscript ναυμ.]. 8.79.1. Ib. there. 6 [Vat. iterum Vatican again ναυμ.]. 8.83.3.