προσπολεμεῖν
From LSJ
Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
Greek > English (Woodhouse Verbs Reversed)
(see also προσπολεμέω): wage war against
Lexicon Thucydideum
bello petere, to attack in war, 7.51.1, 8.96.5, 8.96.5
