Principal

• POS: Adjective, Noun
• HYPHEN: prin=ci=pal

CIDE DICTIONARY

Principal, a. [F., from L. principalis. See Prince.].

•  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.  [1913 Webster]

  "Wisdom is the principal thing."  [1913 Webster]
•  Of or pertaining to a prince; princely.  Spenser.  [1913 Webster]

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.

Principal, n. 

•  A leader, chief, or head; one who takes the lead; one who acts independently, or who has controlling authority or influence; as, the principal of a faction, a school, a firm, etc.; -- distinguished from a subordinate, abettor, auxiliary, or assistant.  [1913 Webster]
•  The chief actor in a crime, or an abettor who is present at it, -- as distinguished from an accessory.  Wharton. Bouvier. Burrill.  [1913 Webster]
•  A thing of chief or prime importance; something fundamental or especially conspicuous.  [1913 Webster]

OXFORD DICTIONARY

Principal, adj. & n.
--adj.
1 (usu. attrib.) first in rank or importance; chief (the principal town of the district).
2 main, leading (a principal cause of my success).
3 (of money) constituting the original sum invested or lent.
--n.
1 a head, ruler, or superior.
2 the head of some schools, colleges, and universities.
3 the leading performer in a concert, play, etc.
4 a capital sum as distinguished from interest or income.
5 a person for whom another acts as agent etc.
6 (in the UK) a civil servant of the grade below Secretary.
7 the person actually responsible for a crime.
8 a person for whom another is surety.
9 each of the combatants in a duel.
10 a a main rafter supporting purlins. b a main girder.
11 an organ stop sounding an octave above the diapason.
12 Mus. the leading player in each section of an orchestra.

Idiom

principal boy (or girl) an actress who takes the leading male (or female) part in a pantomime. principal clause Gram. a clause to which another clause is subordinate. principal in the first degree a person directly responsible for a crime as its actual perpetrator. principal in the second degree a person directly responsible for a crime as aiding in its perpetration. principal parts Gram. the parts of a verb from which all other parts can be deduced.

Derivative

principalship n.

Etymology

ME f. OF f. L principalis first, original (as PRINCE)

THESAURUS

Principal

A per se, English horn, academic dean, ace, administration, administrator, all-absorbing, arch, assets, backing, banner, bassoon, block flute, bombard, boss, bourdon, capital, capital gains distribution, capital structure, capitalization, cardinal, cash reserves, cello, central, chairman, champion, chancellor, chief, chief executive officer, circulating capital, claribel, clarinet, clarion, commander, concert flute, controlling, cornet, cornopean, corpus, cromorna, crowning, cymbel, danseur noble, dean, dean of men, dean of women, diapason, director, diva, dominant, doyen, doyenne, dulciana, electronics king, equity capital, feature attraction, first, first tragedian, fixed capital, floating capital, flute stop, focal, foremost, foundation stop, fourniture, front, fugleman, fund, gamba, gedeckt, gemshorn, genius, great, harmonic flute, head, headliner, headmaster, headmistress, headmost, heavy lead, hegemonic, hero, heroine, high priest, higher-up, highest, honcho, hybrid stop, important, important person, investment, jeune premier, key, king, kingfish, kingpin, koppel flute, larigot, laureate, lead, leader, leading, leading lady, leading light, leading man, luminary, magisterial, maiden, main, major, managing director, master, master spirit, melodia, mixture, money, moneyed capital, mutation stop, nazard, nonpareil, oboe, octave, organ stop, outstanding, overriding, overruling, owner, paragon, paramount, personage, piccolo, plein jeu, posaune, predominant, preeminent, premier, preponderant, president, prevailing, prima ballerina, prima donna, primal, primary, prime, prodigy, prominent, proprietor, protagonist, provost, quint, quintaten, rank, ranket, ranking, rector, reed stop, register, resources, rohr flute, ruler, ruling, senior, sesquialtera, shawm, singer, sovereign, spitz flute, star, starring, stellar, stop, stopped diapason, stopped flute, string diapason, string stop, supereminent, superintendent, superior, superman, superstar, supervisor, supreme, the greatest, the most, tierce, top dog, topflight, topmost, tremolo, trombone, trumpet, twelfth, unda maris, uppermost, venture capital, vibrato, vice-chancellor, viola, virtuoso, voix celeste, vox angelica, vox humana, working capital

ROGET THESAURUS

Principal

Importance

N importance, consequence, moment, prominence, consideration, mark, materialness, import, significance, concern, emphasis, interest, greatness, superiority, notability, weight, value, usefulness, gravity, seriousness, solemnity, no joke, no laughing matter, pressure, urgency, stress, matter of life and death, memorabilia, notabilia, great doings, red-letter day, great thing, great point, main chance, the be all and the end all, cardinal point, substance, gist, sum and substance, gravamen, head and front, important part, principal part, prominent part, essential part, half the battle, sine qua non, breath of one's nostrils, cream, salt, core, kernel, heart, nucleus, keynote, keystone, corner stone, trump card, salient points, top sawyer, first fiddle, prima donna, chief, triton among the minnows, 'it', important, of importance, momentous, material, to the point, not to be overlooked, not to be despised, not to be sneezed at, egregious, weighty, of note, notable, prominent, salient, signal, memorable, remarkable, unforgettable, worthy of remark, worthy of notice, never to be forgotten, stirring, eventful, grave, serious, earnest, noble, grand, solemn, impressive, commanding, imposing, urgent, pressing, critical, instant, paramount, essential, vital, all-absorbing, radical, cardinal, chief, main, prime, primary, principal, leading, capital, foremost, overruling, of vital importance in the front rank, first-rate, superior, considerable, marked, rare, significant, telling, trenchant, emphatic, pregnant, tanti, materially, in the main, above all, kat' exochin, par excellence, to crown all, to beat all, expende Hannibalem!.

Director

N director, manager, governor, rector, comptroller, superintendent, supervisor, straw boss, intendant, overseer, overlooker, supercargo, husband, inspector, visitor, ranger, surveyor, aedile, moderator, monitor, taskmaster, master, leader, ringleader, demagogue, corypheus, conductor, fugleman, precentor, bellwether, agitator, caporal, choregus, collector, file leader, flugelman, linkboy, guiding star, adviser, guide, pilot, helmsman, steersman, steermate, wire-puller, driver, whip, Jehu, charioteer, coachman, carman, cabman, postilion, vetturino, muleteer, arriero, teamster, whipper in, head, head man, head center, boss, principal, president, speaker, chair, chairman, chairwoman, chairperson, captain, superior, mayor, vice president, prime minister, premier, vizier, grand vizier, eparch, officer, functionary, minister, official, red-tapist, bureaucrat, man in office, Jack in office, office bearer, person in authority, statesman, strategist, legislator, lawgiver, politician, statist, statemonger, Minos, Draco, arbiter, boss, political dictator, board, secretary, secretary of state, Reis Effendi, vicar, steward, factor, agent, bailiff, middleman, foreman, clerk of works, landreeve, factotum, major-domo, seneschal, housekeeper, shepherd, croupier, proctor, procurator, ex officio.