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¹principal

adjective prin·ci·pal \ˈprin(t)-s(ə-)pəl, -sə-bəl\

: most important

Full Definition of PRINCIPAL

: most important, consequential, or influential : chief <the principal ingredient> <the region's principal city>

: of, relating to, or constituting principal or a principal(see ²principal)

— prin·ci·pal·ly \-sə-p(ə-)lē, -sə-bə-lē, -splē\ adverb

See principal defined for English-language learners

See principal defined for kids

Usage Discussion of PRINCIPAL

Although nearly every handbook and many dictionaries warn against confusing principle and principal, many people still do. Principle is only a noun; principal is both adjective and noun. If you are unsure which noun you want, read the definitions in this dictionary.

Examples of PRINCIPAL

If any suspect that Griswold was exaggerating, they should reflect on the fact that the principal Supreme Court case justifying the invocation of the national security privilege was based on a governmental lie. —Garry Wills, New York Review of Books, 12 Feb. 2009
Following the agreement, the four principal tobacco companies—Philip Morris, R. J. Reynolds, Brown & Williamson, and Lorillard—raised their prices more than 45 cents per pack. The costs of the settlement, as predicted, were passed on to consumers. —Allan M. Brandt, The Cigarette Century, 2007
Their principal industry was the manufacture, in a long, low, mostly-wooden, two-story factory, of cold cream. —Frederick Busch, Too Late American Boyhood Blues, 1984
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Origin of PRINCIPAL

Middle English, from Anglo-French, from Latin principalis, from princip-, princeps

First Known Use: 14th century

Related to PRINCIPAL

Synonyms: arch, big, capital, cardinal, central, chief, dominant, first, grand, great, greatest, highest, key, leading, main, master, number one (also No. 1), numero uno, overbearing, overmastering, overriding, paramount, predominant, preeminent, premier, primal, primary, foremost, prior, sovereign (also sovran), supreme

Antonyms: last, least

²principal

noun prin·ci·pal \ˈprin(t)-s(ə-)pəl, -sə-bəl\

: the person in charge of a public school

: the person in charge of a university or college

: an amount of money that is put in a bank or lent to someone and that can earn interest

Full Definition of PRINCIPAL

: a person who has controlling authority or is in a leading position: as

a : a chief or head man or woman

b : the chief executive officer of an educational institution

c : one who engages another to act as an agent subject to general control and instruction; specifically : the person from whom an agent's authority derives

d : the chief or an actual participant in a crime

e : the person primarily or ultimately liable on a legal obligation

f : a leading performer : star

: a matter or thing of primary importance: as

a (1) : a capital sum earning interest, due as a debt, or used as a fund (2) : the corpus of an estate, portion, devise, or bequest

b : the construction that gives shape and strength to a roof and is usually one of several trusses; broadly : the most important member of a piece of framing

— prin·ci·pal·ship \ˈprin(t)-s(ə-)pəl-ˌship, -sə-bəl-\ noun

See principal defined for English-language learners

Usage Discussion of PRINCIPAL

Origin of PRINCIPAL

(see ¹principal)

First Known Use: 14th century

Related to PRINCIPAL

Synonyms: headliner, lead, star

Other Education Terms

baccalaureate, colloquium, corequisite, dissertation, monograph, pedant, practicum, survey course, thesis

PRINCIPALLY Defined for Kids

¹principal

adjective prin·ci·pal \ˈprin-sə-pəl\

Definition of PRINCIPAL for Kids

: highest in rank or importance : chief <My sister had the principal part in the school play.>

— prin·ci·pal·ly adverb

²principal

noun

Definition of PRINCIPAL for Kids

: the head of a school

: a leading or most important person or thing

: a sum of money that is placed to earn interest, is owed as a debt, or is used as a fund

Headscratcher for PRINCIPAL

Principal and principle sound the same but have different spellings and different meanings. A principle is a basic truth or theory that people base other ideas on, as in science. A principal is the head of a school. A commonly used way of remembering the spelling is by remembering that the principal is your pal.