What is "challenge to the array"

Challenge \Chal"lenge\, n. [OE. chalenge claim, accusation, challenge, OF. chalenge, chalonge, claim, accusation, contest, fr. L. calumnia false accusation, chicanery. See Calumny.]

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.

   A challenge to controversy.
   --Goldsmith.

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

3. A claim or demand. [Obs.]

   There must be no challenge of superiority.
   --Collier.

4. (Hunting) The opening and crying of hounds at first finding the scent of their game.

5. (Law) 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.
   --Blackstone

6. An exception to a person as not legally qualified to vote. The challenge must be made when the ballot is offered. [U. S.]

   Challenge to the array (Law), an exception to the whole panel.

   Challenge to the favor, the alleging a special cause, the sufficiency of which is to be left to those whose duty and office it is to decide upon it.

   Challenge to the polls, an exception taken to any one or more of the individual jurors returned.

   Peremptory challenge, a privilege sometimes allowed to defendants, of challenging a certain number of jurors (fixed by statute in different States) without assigning any cause.

   Principal challenge, that which the law allows to be sufficient if found to be true.