αὐτὸν κέκρουκας τὸν βατῆρα τοῦ λόγου → you have struck the very threshold of the argument, you have struck the most important and chiefmost point
vinctus: a, um, Part. of vincio.
vinctus: ūs, m. vincio,
I a binding: vinctu, quod antiqui vocabant cestum, Varr. R. R. 1, 8, 6.
(1) vīnctus, a, um, part. de vincio.
(2) vīnctŭs,¹⁵ ūs, m., lien : Varro R. 1, 8, 6.