Principal

a. [Lat. principālis, Fr., Pr., Sp., & Pg. principal, It. principale. See PRINCE.] 1. Highest in rank, authority, character, or importance; most considerable; chief; as, the principal officers of a government; the principal men of a city, town, or state; the principal arguments in a case; the principal beams of a building; the principal productions of a country. Wisdom is the principal thing. Prov. iv. 7. 2. Pertaining to a prince; princely. [A Latinism.] [Obs.] “In the pride of his freedom principal.” Spenser. Principal axis (Conic Sections), the axis which passes through the two foci; in the parabola, the diameter passing through the focus. Math. Dict.—Principal challenge (Law), a challenge of a juror for a cause which carries with it, prima facie, evident marks of suspicion, either of malice or favor. Burrill.—Principal point (Persp.), the projection of the point of sight upon the plane of projection; the center of the picture. Math. Dict.—Principal ray (Persp.), the line drawn through the point of sight perpendicular to the perspective plane. Math. Dict.—Principal section (Crystallog.), a plane passing through the optical axis of a crystal.

n. 1. A chief or head; one who takes the lead; as, the principal of a faction, an insurrection, or mutiny; hence, specifically, (a.) One who possesses or exercises chief authority; as, the principal of a school, or like institution of learning. (b.) One who takes a chief, leading, or independent part, as distinct from an abettor, auxiliary, assistant, and the like. (c.) Hence (Law), the chief actor in a crime, or an abettor who is present at it, as distinguished from an accessory; a chief obligor, promisor, or debtor, as distinguished from a surety; one who employs another to act for him, as distinguished from an agent; also, an heir-loom; a mortuary. Cowell. Wharton. Bouvier. Burrill.

2Sense 2. A thing of chief or prime consequence; as, (a.) (Arch.) A main beam, rafter, or other important timber. Guilt. “The principals and corner-posts of their houses.” Holland. (b.) (Mus.) A metallic stop, originally distinguished by that name because, holding in point of pitch the middle station between the diapason and fifteenth, it forms the standard for tuning the other stops. Moore. (c.) One of the turrets or pinnacles of wax-work and tapers with which the posts and center of a funeral hearse were formerly crowned. Oxf. Gloss.

3Sense 3. A capital sum of money, placed out at interest, due as a debt or used as a fund;—so called in distinction from interest or profit.