κακῶς ποιεῖν
From LSJ
τῶν γὰρ μετρίων πρῶτα μὲν εἰπεῖν τοὔνομα νικᾷ → the first mention of the word moderation wins the game (Euripides, Medea 125f.)
Greek > English (Woodhouse)
harm, injure, do a bad turn, do in injury, do one a bad turn, evilly entreat, treat ill, use ill