principal is on the Academic Word List.

Pronunciation change

Adjective change

Positive
principal

Comparative
none

Superlative
none

  1. (usually before a noun) The principal thing is the main or most important one.
    Canada's principal trading partner is the USA.
    Presumably most of us work for the same principal reason – in order to live.

Related words change

Noun change

Singular
principal

Plural
principals

  1. (countable) In American English, a principal is the head of a school. (headmaster in British English)
  2. (countable) The principal is the most important person in a business, or an artistic group such as a dancers.
  3. (uncountable) Principal is the money that you borrow and must pay back. It does not include interest.