1. a deviation from accuracy or correctness; a mistake, as in action or speech: His speech contained several factual errors.
2. belief in something untrue; the holding of mistaken opinions.
3. the condition of believing what is not true
4. a moral offense; wrongdoing; sin.
5. Baseball. a misplay that enables a base runner to reach base safely or advance a base, or a batter to have a turn at bat prolonged, as the dropping of a ball batted in the air, the fumbling of a batted or thrown ball, or the throwing of a wild ball, but not including a passed ball or wild pitch.