ἐγκ-

From LSJ

μὴ κακὸν εὖ ἔρξῃς· σπείρειν ἴσον ἔστ' ἐνὶ πόντῳ → do no good to a bad man; it is like sowing in the sea

Source

Spanish (DGE)

v. tb. ἐκκ-.