αὐτὸν κέκρουκας τὸν βατῆρα τοῦ λόγου → you have struck the very threshold of the argument, you have struck the most important and chiefmost point
καίαρ: τό (только nom. и acc. sing.) ременная петля (пращи) (Arst. - v. l. βάρος).
