ἐπιγλωσσᾶσθαι κακά

From LSJ

ἀλώπηξ, αἰετοῦ ἅ τ' ἀναπιτναμένα ῥόμβον ἴσχει → a fox, which, by spreading itself out, wards off the eagle's swoop

Source

Greek > English (Woodhouse)

give tongue to evil words