Other forms: overruled; overruling; overrules
In a court of law, when a judge overrules, she disagrees with an attorney's objection and allows the opposing side to go ahead with a line of questioning.
In courtroom dramas, you'll hear lawyers yelling, "Objection!" followed by a judge declaring, "Overruled!" When the court overrules an objection, they're considering the legality of what the opposing attorney was saying and whether the objection was legitimate. If there was a valid legal reason to object, the judge would say, "Sustained." Judges can also overrule previous decisions made by lower courts. Before gaining its legal meaning, overrule simply meant "rule over or govern."