ὑποβαρβαρίζειν

From LSJ

Γιγνώσκεις οὖν καὶ σὺ τὰ στρατηγικὰ ἔργα → Therefore you, too, know the works (i.e. job) of a general.

Source

Greek > English (Woodhouse Verbs Reversed)

talk in barbarous speech (see also: ὑποβαρβαρίζω)