1. A call to engage in a contest, fight, or competition: a challenge to a duel.
2. an act or statement of defiance; a call to confrontation: a challenge to the government's authority.
3. A demand for explanation or justification; a calling into question: a challenge to a theory.
4. A sentry's call to an unknown party for proper identification.
5. A test of one's abilities or resources in a demanding but stimulating undertaking: a career that offers a challenge.
6. A claim that a vote is invalid or that a voter is unqualified.
7. law A formal objection to the inclusion of a prospective juror in a jury.
8. immunology the induction or evaluation of an immune response in an organism by administration of a specific antigen to which it has been sensitized.
9. to call to engage in a contest, fight, or competition: challenged me to a game of chess.
10. to invite with defiance; dare: challenged him to contradict her. see synonyms at defy.
11. to take exception to; call into question; dispute: a book that challenges established beliefs.
12. to order to halt and be identified, as by a sentry.
13. law to take formal objection to (a prospective juror).
14. to question the qualifications of (a voter) or validity of (a vote).
15. to have due claim to; call for: events that challenge our attention.
16. to summon to action, effort, or use; stimulate: a problem that challenges the imagination.
17. immunology to induce or evaluate an immune response in (an organism) by administering a specific antigen to which it has been sensitized.
18. to make or give voice to a challenge.
19. to begin barking upon picking up the scent. used of hunting dogs.

1. an instigation or antagonization intended to convince a person to perform an action they otherwise would not.
2. A difficult task, especially one that the person making the attempt finds more enjoyable because of that difficulty.
3. A bid to overcome something.
4. A judge's interest in the result of the case for which he or she should not be allowed to sit the case, e.g. a conflict of interest.
5. the act of appealing a ruling or decision of a court of administrative agency.
6. the act of seeking to remove a judge, arbitrator or other judicial or semi-judicial figure for reasons of alleged bias or incapacity.
7. an attempt to take possession; a tackle
8. to invite someone to take part in a competition.
9. to dare someone.
10. to dispute something.
11. to make a formal objection to a juror.

1. an invitation to engage in a contest or controversy of any kind; a defiance; specifically, a summons to fight a duel; also, the letter or message conveying the summons.
2. the act of a sentry in halting any one who appears at his post, and demanding the countersign.
3. A claim or demand.
4. the opening and crying of hounds at first finding the scent of their game.
5. 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.
6. an exception to a person as not legally qualified to vote. the challenge must be made when the ballot is offered.
7. to assert a right; to claim a place.
8. to call to a contest of any kind; to call to answer; to defy.
9. to call, invite, or summon to answer for an offense by personal combat.
10. to claim as due; to demand as a right.
11. to censure; to blame.
12. to question or demand the countersign from (one who attempts to pass the lines)
13. to take exception to; question.
14. to object to or take exception to, as to a juror, or member of a court.
15. to object to the reception of the vote of, as on the ground that the person in not qualified as a voter.

1. to accuse; call to answer; censure.
2. to lay claim to; demand as due or as a right: as, the supreme being challenges our reverence and homage.
3. to call, invite, or summon to single combat or duel.
4. to call to a contest; call into opposing activity; invite to a trial; defy: as, to challenge a man to prove what he asserts (implying defiance).
5. to take exception to; object to (a person or thing); call in question: as, to challenge the accuracy of a statement. specifically
6. in law, to object or take exception to, as a juror or jury panel. see challenge, n., 9—7. Milit., to demand the countersign from: as, a sentry is bound to challenge every person appearing near his post. see challenge, n., 6.
7. in hunting, to whimper or cry when the scent of game is first discovered: said of a hound.
8. accusation; charge.
9. A claim or demand; pretension.
10. A summons or invitation to a duel; a calling upon one to engage in single combat, as for the vindication of the challenger's honor; a defiance.
11. hence an invitation to a contest or trial of any kind: as, a challenge to a rubber at whist; a challenge to a public debate; “a challenge to controversy,”
12. the letter or message containing the summons to a combat or contest.
13. Milit., the act of a sentry in demanding the countersign from any one who approaches his post.
14. in hunting, the opening cry of hounds on first finding the scent of their game.
15. A calling in question; an exception taken, as to the tenability of a proposition, or a person's right to do something or to hold something.
16. in law, an objection to a juror; the claim of a party that a certain juror shall not sit in the cause.
17. in the east indies, an exception taken by a ryot to the assessment of a neighbor's holding when it is less than that of his own poorer holding, accompanied by an offer to take over the neighbor's holding at a higher assessment, and a claim for the assessment on his own to be correspondingly reduced.

1. take exception to
2. a call to engage in a contest or fight
3. a demand by a sentry for a password or identification
4. a formal objection to the selection of a particular person as a juror
5. ask for identification
6. a demanding or stimulating situation
7. issue a challenge to
8. raise a formal objection in a court of law
9. questioning a statement and demanding an explanation