ἀδιάσφαλτος
From LSJ
λύχνον μεθ' ἡμέραν ἅψας περιῄει λέγων ἄνθρωπον ζητῶ → he lit a lamp in broad daylight and said, as he went about, I am looking for a man
English (LSJ)
ον, free from error, μέθοδοι Hero *Geep.164. Adv. ἀδιασφάλτως Ps.-Dioph.p.xxi H.
Spanish (DGE)
-ον infalible μέθοδον Hero Lib.Geep.164.