principle

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

|Updated on: 17 Jun 2018

Usage guide: principle vs. principal

Examples: principle in a Sentence

Editor's Note: principle vs. principal

Definition of principle

1 a : a comprehensive and fundamental law, doctrine, or assumption

b (1) : a rule or code of conduct

(2) : habitual devotion to right principles

a man of principle

c : the laws or facts of nature underlying the working of an artificial device

2 : a primary source : origin

3 a : an underlying faculty or endowment

such principles of human nature as greed and curiosity

b : an ingredient (such as a chemical) that exhibits or imparts a characteristic quality

4 capitalized, Christian Science : a divine principle : god

— in principle

: with respect to fundamentals

prepared to accept the proposition in principle

See principle defined for English-language learners

See principle defined for kids

principle vs. 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 principle in a Sentence

Urban guerrilla warfare was futile against a thermonuclear superstate that would stop at nothing to defend the profit principle. —Philip Roth, American Pastoral, 1997
Better, of course, to take a higher road, operate on the principle of service and see if things don't turn out better … —Richard Ford, Independence Day, 1995
Pointlessness was life's principle, and it spread its sadness. —Arthur Miller, Timebends, 1987
His investment strategy is based on the principle that the stock market offers the best returns for long-term investors.
the basic principles of hydraulics

Recent Examples of principle from the Web

Can either team maintain their defensive principles while also going in search of a positive result?

— SI.com, "World Cup Preview: Morocco vs Iran -Recent Form, Team News, Predictions & More," 14 June 2018
Under its principles, Internet providers shouldn't interfere with your ability to reach the websites, apps or services of your choice.

— the washington post, OregonLive.com, "Net neutrality repeal kicks in; here's what that means," 11 June 2018
Under its principles, Internet providers shouldn't interfere with your ability to reach the websites, apps or services of your choice.

— brian fung, chicagotribune.com, "FCC's net neutrality rules are officially repealed Monday. Here's what that really means.," 11 June 2018
There has always been a tension in the U.S. between our aspirations to national greatness and our egalitarian principles.

— jay cost, WSJ, "The Founding Era’s Populist Moment," 8 June 2018
Religious groups, however, said that the government shouldn’t force anyone to go against their principles to make a living.

— natalie dreier, ajc, "Supreme Court decision on wedding cake case: Things to know," 5 June 2018
For the past 100 years, its principle has remained the same: air and fuel go in, an explosion happens in the cylinders, and power shoves you onward.

— blake z. rong, Popular Mechanics, "The Evolution of the Combustion Engine," 5 June 2018
Anyone can edit Wikipedia based on our core principles of neutrality and reliable sourcing, and hundreds of thousands of volunteers do this every month.

— james rogers, Fox News, "Google and other tech giants could face hearings if anti-conservative bias continues, lawmaker warns," 4 June 2018
The movement, with its six-core principles, asks the faithful to reject policies that ban refugees and immigrants.

— paula rogo, Essence.com, "Bishop Michael Curry Says He Prays For President Trump," 27 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'principle.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

principle vs. principal

Yes, these two words are confusing; we see evidence of the misuse of both in newspapers and books which have been overseen by professional editors, so don’t feel bad if you have trouble with them. Principle only functions as a noun (such as “a comprehensive and fundamental law, doctrine, or assumption”); if you want it to be an adjective you must use the word principled. Principal, on the other hand, may function as a noun (such as the head of a school) or as an adjective (meaning “most important”).

Origin and Etymology of principle

Middle English, from Middle French principe, principle, from Old French, from Latin principium beginning, from princip-, princeps initiator — more at prince

NEW! Time Traveler

First Known Use: 14th century

in the meaning defined at sense 1a

See Words from the same year

PRINCIPLE Defined for English Language Learners

principle

noun

Definition of principle for English Language Learners

: a moral rule or belief that helps you know what is right and wrong and that influences your actions
: a basic truth or theory : an idea that forms the basis of something
: a law or fact of nature that explains how something works or why something happens