(baseball) a failure of a defensive player to make an out when normal play would have sufficed WordNet 3.0 & Open English WordNet

In baseball and softball statistics, an error is an act, in the judgment of the official scorer, of a fielder misplaying a ball in a manner that allows a batter or baserunner to advance one or more bases or allows a plate appearance to continue after the batter should have been put out. Wikipedia

Mistake by a fielder Wikipedia Disambiguation

In baseball, misplaying of the ball by a fielder, resulting in runner advancement and/or failure to obtain an out Wikidata