ἀψευδέω

A. not to lie, to speak truth, πρός τινα S. Tr. 469, Aeschin. 2.95: abs., Ar. Fr. 751; not to err, Pl. Tht. 199b; περί τι Arist. SE 165a25.

II. observe faithfully, IG 5(2).343.38,57 (Orchom. Arc., iv B. C.).