αὐτὸν κέκρουκας τὸν βατῆρα τοῦ λόγου → you have struck the very threshold of the argument, you have struck the most important and chiefmost point
Ar. and V. εὔγλωσσος (Aesch., Supp. 775), Ar. εὔπορος, V. εὔτροχος.
