ἀψευδέω
From LSJ
ἄμεινον γὰρ ἑαυτῷ φυλάττειν τὴν ἐλευθερίαν τοῦ ἑτέρων ἀφαιρεῖσθαι → for it is better to guard one's own freedom than to deprive another of his
English (LSJ)
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.SE165a25. II observe faithfully, IG5(2).343.38,57 (Orchom. Arc., iv B. C.).