ἀπαρέκτρεπτος
From LSJ
Ἔοικα γοῦν τούτου γε σμικρῷ τινι αὐτῷ τούτῳ σοφώτερος εἶναι, ὅτι ἃ μὴ οἶδα οὐδὲ οἴομαι εἰδέναι → I seem, then, in just this little thing to be wiser than this man at any rate, that what I do not know I do not think I know either
Spanish (DGE)
-ον
que no puede ser desviado, inflexible τὸ βέλτιστον αὐτῆς (νόμου) Plu.2.745d.