principle

noun

prin·​ci·​ple ˈprin(t)-s(ə-)pəl How to pronounce principle (audio)
-sə-bəl
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
Principle vs. Principal: Usage Guide

Evidence of confusion between principle and principal can be found even in publications overseen by professional editors. To keep these words straight, remember that principle functions only as a noun, and in its most common uses refers to a basic rule or law, as in

a guiding principle

or

a matter of principle.

If you are looking for an adjective form of this word, you must use principled, as in

taking a principled stand.

Principal functions as both a noun and an adjective. The noun has various meanings referring to someone with controlling authority

the school principal

or in a leading position

the ballet's two principals

, but also has meanings relating to finance, law, and architecture. As an adjective, principal typically means "most important," as in

the principal reason.

Phrases
in principle
: with respect to fundamentals
prepared to accept the proposition in principle

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 on the Web Consent is a fundamental principle that underpins our interactions in both the physical and digital realms. Alexandru Voica, Fortune, 11 Mar. 2024 The principle even overrides conventionally polite gestures. Judith Martin, The Mercury News, 11 Mar. 2024 With a profound grasp of accounting principles and tax regulations, Certified Public Accountants are invaluable advisors for navigating financial complexities and ensuring adherence to legal standards. Bryce Welker, Miami Herald, 7 Mar. 2024 In principle, mining companies are not opposed to providing the government with information about energy consumption, claims Bratcher. Joel Khalili, WIRED, 6 Mar. 2024 The framework for restitutions was drafted during the Washington Conference on Holocaust Era Assets in 1998 and consists of 11 non-binding principles meant to guide countries with different legal systems through issues related to art seized during the Nazi era within the context of their own laws. Carlie Porterfield, CNN, 6 Mar. 2024 The council approved the resolution 4-1, with Councilmember Dan Quirk opposed, after removing all of the guiding principles except No. 1, stating that moving the train tracks off the bluff is a top priority. Quirk, who opposes the tunnel, said the guiding principles are inadequate. Phil Diehl, San Diego Union-Tribune, 6 Mar. 2024 But that relationship blew up publicly last week when Musk filed a lawsuit against OpenAI and two of its executives, CEO Sam Altman and President Greg Brockman, accusing them of violating those founding principles by putting profits over humanity. Aimee Picchi, CBS News, 6 Mar. 2024 The collapse of the fiat money system and the accompanying welfare-warfare state also provide an opportunity for those of us who understand the truth to build a society based around the principles of liberty. Ron Paul, Orange County Register, 5 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'principle.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

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

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

Dictionary Entries Near principle

Cite this Entry

“Principle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/principle. Accessed 19 Mar. 2024.

Kids Definition

principle

noun
prin·​ci·​ple ˈprin(t)-s(ə-)pəl How to pronounce principle (audio)
-sə-bəl
1
: a general or basic truth on which other truths or theories can be based
scientific principles
2
: a rule of conduct
a person of high principles
3
: a law or fact of nature which makes possible the working of a machine or device
the principle of magnetism
the principle of the lever

Medical Definition

principle

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

More from Merriam-Webster on principle

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