If you describe someone's judgment or ability as unerring, you mean that they are always correct and never mistaken. She has an unerring instinct for people's weak spots. = infallible + unerringly un·err·ing·ly It was wonderful to watch her fingers moving deftly and unerringly. always right
Committing no mistake; incapable or error or failure certain; sure; unfailing; as, the unerring wisdom of God