ἀνεξεύρετος
From LSJ
ἑὰν δὲ προσποιούμενος ᾗ τὰ μαθήματά πως ἀπείρως προβάλλων, οὐκ ἔστιν αἰτίας ἔξω → But should one profess knowledge as he puts forward something in an inexperienced way, he is not without blame (Pappus 3.1.30.31f.)
English (LSJ)
ον,
A not to be found out, ἀριθμός Th. 3.87, cf. Hellanic.194J., Arist.Mu.392a17, Plu.2.964a.