principaladj/ˈpɹɪn.sɪ.pəl/

• 1

  Primary; most important; first level in importance.

  • Smith is the principal architect of this design.
  • The principal cause of the failure was poor planning.
• 2

  obsoleteOf or relating to a prince; princely.

  • But walkt at will, and wandred to and fro, / In the pride of his freedome principall.
• 3

  mathematicssciencesChosen or assumed among a branch of possible values of a multi-valued function so that the function is single-valued.

  • Two is the principal square root of 4. Both −2 and +2 are square roots of 4.

principalnoun/ˈpɹɪn.sɪ.pəl/

• 1

  businessfinanceThe money originally invested or loaned, on which basis interest and returns are calculated.

  • A portion of your mortgage payment goes to reduce the principal, and the rest covers interest.
  • In March 1902, I find in the statement of liabilities and assets £711 put down as arrears of interest, but there is no entry of arrears of principal.
• 2

  The chief administrator of a school.

  • The important administrative figure to the teacher is the school principal.
  • The problem was neatly summed up by one principal in Australia who said recently: ‘There is no incentive for me to develop my best teachers to become my successor.[…]’
• 3

  The chief executive and chief academic officer of a university or college.

  • 1967, University of Edinburgh Graduates′ Association, University of Edinburgh Journal, Volumes 23-24, page 314, Unlike the students, Principal Robertson, who now resided almost alone in the College, continued to use the accustomed route on his visits to the Old Town; and it “became the joke of the day that from being the principal gate it had become only a gate for the Principal.”⁵
  • Coordinate term: bursar
• 4

  lawA legal person that authorizes another (the agent) to act on their behalf; or on whose behalf an agent or gestor in a negotiorum gestio acts.

  • When an attorney represents a client, the client is the principal who permits the attorney, the client′s agent, to act on the client′s behalf.
  • My principal sells metal shims.
• 5

  lawThe primary participant in a crime.

  • The accessories may be prosecuted, tried and punished, though the principal has not been prosecuted or has been acquitted.
• 6

  Either party in a duel.

  • The old man raised his arm as though it had been palsied, and fired, of course without effect. The other principal immediately deloped, much to the satisfaction of my friend and all present.
• 7

  A partner or owner of a business.

• 8

  entertainmentlifestylemusicA type of stop on a pipe organ consisting of flue pipes with a bright tonal quality. They are also sometimes referred to as a diapason.