ἔκλαμπρος
From LSJ
αὐτὸν κέκρουκας τὸν βατῆρα τοῦ λόγου → you have struck the very threshold of the argument, you have struck the most important and chiefmost point
English (LSJ)
ον,
A very bright, φλόγες LXX Wi.17.5, cf. Sch.Arat. 169 : neut. as Adv., ἔκλαμπρον γελᾶν Ath.4.158d. Regul.Adv. -ρως brilliantly, Annuario3.151 (Pisidia, ἐγλ-lapis).
German (Pape)
[Seite 766] sehr glänzend, sehr hell, Sp.; ἔκλαμπρον γελᾶν, hell auflachen, Ath. IV, 158 d.