principle

noun
prin·​ci·​ple | \ ˈprin(t)-s(ə-)pəl How to pronounce principle (audio) , -sə-bəl \

Definition of principle

1a : 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
3a : 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

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Principle vs. Principal: Usage Guide

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.

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”). 

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
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Recent Examples on the Web For entrepreneurs who often experience serial failure and defeat, this principle is particularly relevant. Srini Pillay, Quartz at Work, "Picturing your own success can make you more successful," 21 Feb. 2020 Week 1196, combine two halves of hyphenated words into a new word: Evangelifunctory: Paying lip service to conservative Christian principles. Washington Post, "Style Conversational Week 1372: The punliness of the long-distance runner," 20 Feb. 2020 The need to restate that basic principle is a tacit admission that it is significantly eroded. Eamon Lynch, Golfweek, "Lynch: The USGA's distance report is out, and so begins the battle for golf's future," 4 Feb. 2020 As a reporter and moderator, Gwen was dedicated to two principles: getting the story right and getting the right stories out. Yesha Callahan, Essence, "Journalist Gwen Ifill Honored With Black Heritage Forever Stamp," 30 Jan. 2020 Yet aid workers, traditionally protected by the rules of war and a commitment to humanitarian principles, are increasingly under threat. David Miliband, Quartz, "Davos is ignoring one of the most devastating humanitarian crises of our time," 23 Jan. 2020 Such a holding is contrary to American principles of justice that I have been taught since elementary school. Time, "A Federal Court Threw Out A High Profile Climate Lawsuit. Here's What It Might Mean For The Future of Climate Litigation," 19 Jan. 2020 According to the Very Well Mind' s principles of color psychology, the shade of brown stands for strength and reliability. Bianca Rodriguez, Marie Claire, "Meghan Markle, the Queen, & Kate Middleton Have All Worn a Lot of Brown Lately," 15 Jan. 2020 Kwanzaa was first observed in the 1960s as a mean of helping African Americans reconnect with their cultural heritage, and each of its seven days is devoted to a principle of African life, including faith, purpose and self-determination. Greg Crawford, Detroit Free Press, "Detroit's Top 10: Cool things to do this week, including New Year's Eve fun, the Roots, Jeff Daniels, Kwanzaa," 25 Dec. 2019

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.

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First Known Use of principle

14th century, in the meaning defined at sense 1a

History and Etymology for principle

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

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Learn More about principle

Time Traveler for principle

Time Traveler

The first known use of principle was in the 14th century

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Statistics for principle

Last Updated

25 Feb 2020

Cite this Entry

“Principle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/principle. Accessed 27 Feb. 2020.

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More Definitions for principle

principle

noun
How to pronounce principle (audio)

English Language Learners Definition of principle

: 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

principle

noun
prin·​ci·​ple | \ ˈprin-sə-pəl How to pronounce principle (audio) \

Kids Definition of principle

1 : a general or basic truth on which other truths or theories can be based scientific principles
2 : a rule of conduct based on beliefs of what is right and wrong
3 : a law or fact of nature which makes possible the working of a machine or device the principle of magnetism

principle

noun
prin·​ci·​ple | \ ˈprin(t)-sə-pəl How to pronounce principle (audio) \

Medical Definition of principle

1 : a comprehensive and fundamental law, doctrine, or assumption
2 : an ingredient (as a chemical) that exhibits or imparts a characteristic quality the active principle of a drug

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Comments on principle

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