1. An apprehending wrongly; a misconception; a misunderstanding; a fault in opinion or judgment; an unintentional error of conduct. Infallibility is an absolute security of the understanding from all possibility of mistake. (Tillotson)
2. Misconception, error, which when non-negligent may be ground for rescinding a contract, or for refusing to perform it. No mistake, surely; without fail; as, it will happen at the appointed time, and no mistake.