Logo
dictionary thesaurus

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
Principle vs. Principal: Usage Guide Principle vs. Principal More Example Sentences Learn More about principle

Keep scrolling for more

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
See More

Recent Examples on the Web

 Based on my observations over the last decade, his whole operation runs on two simple but powerful principles. — Evgeny Morozov, The New Republic, "Jeffrey Epstein’s Intellectual Enabler," 22 Aug. 2019 As Claremont puts a great deal of effort into promoting constitutional principles and the Founding, this is a peculiarly off-base sally. — Kyle Smith, National Review, "The Movies Take On Limbaugh, Levin, et al.," 21 Aug. 2019 Last year was foundational, focused on implementation of offensive coordinator Marcus Arroyo’s scheme, its plays and principles and incorporating newer players into it. — James Crepea | The Oregonian/oregonlive, oregonlive.com, "How Oregon’s offense is more ‘advanced’ compared to 2018," 21 Aug. 2019 Slowly the boys learn the principle that only a sinner is worthy of a priest’s, or God’s, consideration. — Tim Parks, Harper's magazine, "Murder Italian Style," 19 Aug. 2019 Fundamental freedoms, including the right of peaceful assembly, and Hong Kong’s high degree of autonomy under the ‘one country, two systems’ principle, are enshrined in the Basic Law and in international agreements and must continue to be upheld. — Alexandra Ossola, Quartz, "With Trump silent, Canada and the EU urge de-escalation in Hong Kong," 18 Aug. 2019 Despite choosing Cranbrook Academy of Art over Taliesin in his youth, Kaeser’s prolific career was clearly influenced by Wright’s organic principles. — Megan Barber, Curbed, "Frank Lloyd Wright-inspired ranch asks $900K," 14 Aug. 2019 The fundamental counting principle gives us a total of q × (q – 1) × 1 × (q – 1) = q(q – 1)2 possible seatings. — Quanta Magazine, "Color Me Polynomial," 13 Aug. 2019 This is inherently incongruent to the principles and methodology of XR and FFF. — Manavi Kapur, Quartz India, "Global movement Extinction Rebellion is spawning India’s future climate change warriors," 24 July 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.

See More

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

Keep scrolling for more

Keep scrolling for more

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

See the full definition for principle in the English Language Learners Dictionary

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

Keep scrolling for more

WORD OF THE DAY

convivial

play

See Definitions and Examples

Get Word of the Day daily email!