ἀδιάσφαλτος
From LSJ
οὔτε σοφίας ἐνδείᾳ οὔτ' αἰσχύνης περιουσίᾳ → neither from lack of knowledge nor from superfluity of modesty
English (LSJ)
ον, A free from error, μέθοδοι Hero *Geep.164. Adv. -τως Ps.-Dioph.p.xxi H.
Spanish (DGE)
-ον infalible μέθοδον Hero Lib.Geep.164.