The act of a sentry in halting any one who appears at his post, and demanding the countersign.

A claim or demand.

An exception to a juror or to a member of a court martial, coupled with a demand that he should be held incompetent to act; the claim of a party that a certain person or persons shall not sit in trial upon him or his cause.

To claim as due; to demand as a right.

To question or demand the countersign from (one who attempts to pass the lines); as, the sentinel challenged us, with "Who comes there?"

To assert a right; to claim a place.

A test of one's abilities or resources in a demanding but stimulating undertaking.

a demanding or stimulating situation; "they reacted irrationally to the challenge of Russian power"

questioning a statement and demanding an explanation; "his challenge of the assumption that Japan is still our enemy"

a demand by a sentry for a password or identification

A claim that the records on file with a law enforcement agency do not accurately reflect the actions taken by the court. A challenge will not address whether the action taken by the court was proper or not.