μὴ κακὸν εὖ ἔρξῃς· σπείρειν ἴσον ἔστ' ἐνὶ πόντῳ → do no good to a bad man; it is like sowing in the sea
Use Ar. and P. ξύλον, τό, P. and V. κλῷος, ὁ (Euripides, Cyclops 235).
Met., brand with disgrace: P. εἰς στήλην γράφειν.
