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Meaning & use

principal

adjective, noun·Academic

Last updated

UK/ˈprɪnsəpəl/
US/ˈprɪnsəpəl/

Meanings

  1. adjectivebefore a noun

    Most important; main.

    Grammar: Used before a noun: the principal reason. It is not usually used after a verb (not 'the reason is principal').

    Patterns

    • principal reason
    • principal source
    • principal aim

    The principal reason for the delay was bad weather.

    She is the principal investigator on the project.

    Tourism is the principal source of income for the island.

  2. nouncountableAmerican

    The person in charge of a school.

    Grammar: Used mainly in American English; in British English the usual word is 'head teacher' or 'head'.

    Patterns

    • school principal
    • the principal of a school

    The principal announced that the school would close early.

    I was sent to the principal's office for being late.

  3. nounsingularfinance

    An amount of money lent or invested, not including interest.

    Grammar: Often used in finance: repay the principal. It contrasts with 'interest'.

    Patterns

    • repay the principal
    • the principal on a loan

    You can pay off the principal at any time without a fee.

    The monthly payment covers both principal and interest.

Common combinations

principal reason
The principal reason for the meeting was to discuss the budget.
principal source
The sun is our principal source of energy.
school principal
The school principal gave a speech at the graduation.
principal and interest
The loan requires monthly payments of principal and interest.

Synonyms and how they differ

main
Very close in meaning, but 'main' is more common in everyday speech; 'principal' is slightly more formal.
chief
Often used for people or roles (chief executive); 'principal' is more often used for things or reasons.
primary
Emphasizes first in order or importance; 'principal' emphasizes highest rank.

Opposites

secondaryminor

Word family

principally adverb
Mainly; for the most part.
principality noun
A country ruled by a prince or princess.

Commonly confused: principal or principle?

principal vs principle

Principle means a basic rule or belief (e.g., 'a matter of principle'). Principal means main, a school head, or a sum of money.

Practice

The ___ reason for the change was to save money.

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