What is "principal challenge"

Principal \Prin"ci*pal\, a. [F., from L. principalis. See Prince.]

1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a state; the principal productions of a country; the principal arguments in a case.

   Wisdom is the principal thing.
   --Prov. iv. 7.

2. Of or pertaining to a prince; princely. [A Latinism] [Obs.]
   --Spenser.

   Principal axis. See Axis of a curve, under Axis.

   Principal axes of a quadric (Geom.), three lines in which the principal planes of the solid intersect two and two, as in an ellipsoid.

   Principal challenge. (Law) See under Challenge.

   Principal plane. See Plane of projection (a), under Plane.

   Principal of a quadric (Geom.), three planes each of which is at right angles to the other two, and bisects all chords of the quadric perpendicular to the plane, as in an ellipsoid.

   Principal point (Persp.), the projection of the point of sight upon the plane of projection.

   Principal ray (Persp.), the line drawn through the point of sight perpendicular to the perspective plane.

   Principal section (Crystallog.), a plane passing through the optical axis of a crystal.

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.