principal: Meaning and Definition of

prin•ci•pal

1. first or highest in rank, importance, value, etc.; chief; foremost.
2. of, of the nature of, or constituting principal or capital: a principal investment.
3. (of an axis of a conic) passing through the foci.

1. a chief or head.
2. the head or director of a school or, esp. in England, a college.
3. a person who takes a leading part in any activity, as a play; chief actor or doer.
4. the first player of a division of instruments in an orchestra (excepting the leader of the first violins).
5. something of principal or chief importance.
1. a person who authorizes another, as an agent, to represent him or her.
2. a person directly responsible for a crime, either as an actual perpetrator or as an abettor present at its commission. Cf.accessory(def. 3).
7. a person primarily liable for an obligation, in contrast with an endorser, or the like.
8. the main body of an estate, or the like, as distinguished from income.
9. a capital sum, as distinguished from interest or profit.
1. an organ stop.
2. the subject of a fugue.
11. (in a framed structure) a member, as a truss, upon which adjacent or similar members depend for support or reinforcement.
12. each of the combatants in a duel, as distinguished from the seconds.