principal
principal (prĭnʹsə-pəl) adjective
Abbr. prin.
1. First, highest, or foremost in importance, rank, worth, or degree; chief. See synonyms at chief.
2. Of, relating to, or being financial principal, or a principal in a financial transaction.
noun
Abbr. prin.
1. One who holds a position of presiding rank, especially the head of an elementary school or high school.
2. A main participant in a situation.
3. A person having a leading or starring role.
4. a. The capital or main body of an estate or a financial holding as distinguished from the interest or revenue from it. b. A sum of money owed as a debt, upon which interest is calculated.
5. Law. a. A person who empowers another to act as his or her representative. b. The person having prime responsibility for an obligation as distinguished from one who acts as surety or as an endorser. c. One who commits or is an accomplice to a crime.
6. The main truss or rafter that supports and gives form to a roof.
[Middle English, from Old French, from Latin prīncipālis, from prīnceps, prīncip-, leader, emperor.]
prinʹcipally adverb
prinʹcipalship noun
Usage Note: Principal and principle are often confused but have no meanings in common. Principle is only a noun, and most of its senses refer to that which is basic or to rules and standards. Principal is both a noun and an adjective. As a noun (aside from its specialized meanings in law and finance) it generally denotes a person who holds a high position or plays an important role: a meeting among all the principals in the transaction. As an adjective it has the sense of "chief" or "leading."