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

Her news outlet must decide whether to short its readers on coverage of a gubernatorial candidate on a matter of principle, or capitulate to the candidate’s insulting demands. Monica Hesse, Washington Post, "The ‘Billy Graham Rule’ doesn’t honor your wife. It demeans her — and all women.," 11 July 2019 Celebrate Recovery meeting, 7 p.m., Calvary Chapel Ramona, 114 14th St. The 12 Step program is based on Biblical principles. 858-842-0493. Ramona Sentinel, "Our Town Calendar of Events: July 12-17," 10 July 2019 Focusing on the principles and mathematics that AI and neuroscience share can help advance research into both fields, achieving new levels of ability for computers and understanding of natural brains. Gabriel A. Silva, The Conversation, "Neuroscience and artificial intelligence can help improve each other," 9 July 2019 This season, which is still months away, is about building -- off the positives from last year, a workable system and culture based on the principles that matter most in this era. Chris Fedor, cleveland.com, "Cleveland Cavaliers and John Beilein’s search for ‘small victories’ that will define the season -- Chris Fedor," 3 July 2019 Not collecting data was a core principle when Blue Dot was founded, says Corcoran, a nod to the volunteers’ interest in maintaining psychological safety for everyone involved in the program. Lila Maclellan, Quartz at Work, "Google is running an employee mental health project without any metrics," 25 June 2019 In 1930, Popenoe opened a counseling clinic to redress the devastating impact of feminism on the American family and instruct on the principles of good breeding. Audrey Farley, Longreads, "We Still Don’t Know How to Navigate the Cultural Legacy of Eugenics," 20 June 2019 The driving principle is conserving as much open space as possible. Diana Budds, Curbed, "This suburban utopia is all about worshipping nature," 14 June 2019 The household of a playwright is likely to have been organized on similar principles. Phyllis Rackin, The Atlantic, "The Hidden Women Writers of the Elizabethan Theater," 8 June 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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Statistics for principle

Last Updated

15 Jul 2019

Look-up Popularity

Time Traveler for principle

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

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More Definitions for principle

principle

noun

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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