Having or exercising sound judgement or discernment; capable of judging truly concerning what is right or fitting, and disposed to act accordingly…

Quite certain, sure, unerring. (Cf. dead certainty in sense A. 31a.) dead shot, one whose aim is certain death; so dead on the bird. dead-on…

figurative. Not liable to fail or make a mistake; characterized by confidence or competence; assured; unerring.

= unerring, adj.

Making no error or mistake; not going or leading astray in judgement or opinion.

Unquestionably true; established as fact. Obsolete. rare.

Without error; free from fault or mistake.

Not erroneous, without error or mistake.