Principal

Principal may refer to:

Education

The head of an educational institution:
*Principal (school), head of a primary or secondary school
*Principal (university), chief executive of a university
**Dean (education), a person with significant authority
**Provost (education), chief academic officer of a university
**Chancellor (education), the head of a university

Law

*Principal (commercial law), a person who authorises an agent to act to create a legal relationship with a third party
* Principal (criminal law), one (or more) primary actor(s) in a criminal offense for which other actors may be criminally liable as accomplices, accessories or conspirators

Other uses

* Principal sum, the original amount of a debt or investment on which interest is calculated
* Organ stop on a pipe organ
* A musician in an orchestra who either plays the first part (wind instruments), or who sits in the first chair and leads a section (of string instruments) in playing the same part
* A performer in an opera or musical who takes a more or less prominent part in the action, and sings solo or in small ensembles
* Principal value, values along a chosen branch of a multivalued function
** The principal values of the different inverse trigonometric functions are a common example.
* Principal branch, a special selected branch of a multivalued function
* Principal ideal, in ring theory in mathematics, an ideal with a single generator, and the related concept of principal ideal domains
* The Cauchy Principal Value of an integral, in mathematics, a way of assigning a finite value to improper integrals that seem to diverge
* Principal (Civil Service) or Principal Officer, a senior management grade (now grade 7) in the British Civil Service and the Irish Civil Service
* A security principal is an entity that can be positively identified and verified via a technique known as Authentication
* Principal, Cape Verde, a village
* Principal Financial Group, a life insurance company traded on the NYSE