To invite someone to engage in a contest or competition. She challenged him to a game of chess.
To question the validity or truth of something. The lawyer challenged the witness's testimony.
To confront or defy someone or something. He challenged the authority of the new manager.
To stimulate or provoke someone to do something difficult or demanding. The teacher challenged the students to think critically about the topic.
To raise a formal legal objection to (a prospective juror or a piece of evidence) during a trial. The defense attorney challenged the admissibility of the surveillance footage.