ἀδιάσφαλτος
From LSJ
ἀκμὴ οὐδὲ ἔχει γενέσεως ὑπόστασιν καθ' ἑαυτήν → the culmination has no power of originating by itself
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.