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principle

American  
[prin-suh-puhl] / ˈprɪn sə pəl /

noun

  1. an accepted or professed rule of action or conduct.

    a person of good moral principles.

  2. a fundamental, primary, or general law or truth from which others are derived.

    the principles of modern physics.

    Synonyms:
    proposition, postulate, axiom, theorem
  3. a fundamental doctrine or tenet; a distinctive ruling opinion.

    the principles of the Stoics.

  4. principles, a personal or specific basis of conduct or management.

    to adhere to one's principles; a kindergarten run on modern principles.

  5. guiding sense of the requirements and obligations of right conduct.

    a person of principle.

    Synonyms:
    honor, rectitude, probity, integrity
  6. an adopted rule or method for application in action.

    a working principle for general use.

  7. a rule or law exemplified in natural phenomena, the construction or operation of a machine, the working of a system, or the like.

    the principle of capillary attraction.

  8. the method of formation, operation, or procedure exhibited in a given case.

    a community organized on the patriarchal principle.

  9. a determining characteristic of something; essential quality.

  10. an originating or actuating agency or force.

    growth is the principle of life.

  11. an actuating agency in the mind or character, as an instinct, faculty, or natural tendency.

    the principles of human behavior.

  12. Chemistry. a constituent of a substance, especially one giving to it some distinctive quality or effect.

  13. Obsolete. beginning or commencement.


idioms

  1. in principle, in essence or substance; fundamentally.

    to accept a plan in principle.

  2. on principle,

    1. according to personal rules for right conduct; as a matter of moral principle.

      He refused on principle to agree to the terms of the treaty.

    2. according to a fixed rule, method, or practice.

      He drank hot milk every night on principle.

principle 1 British  
/ ˈprɪnsɪpəl /

noun

  1. a standard or rule of personal conduct

    a man of principle

  2. (often plural) a set of such moral rules

    he'd stoop to anything

    he has no principles

  3. adherence to such a moral code; morality

    it's not the money but the principle of the thing

    torn between principle and expediency

  4. a fundamental or general truth or law

    first principles

  5. the essence of something

    the male principle

  6. a source or fundamental cause; origin

    principle of life

  7. a rule or law concerning a natural phenomenon or the behaviour of a system

    the principle of the conservation of mass

  8. an underlying or guiding theory or belief

    the hereditary principle

    socialist principles

  9. chem a constituent of a substance that gives the substance its characteristics and behaviour

    bitter principle

  10. in theory or essence

  11. because of or in demonstration of a principle

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Principle 2 British  
/ ˈprɪnsɪpəl /

noun

  1. Christian Science another word for God

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

principle More Idioms  

Usage

Principle and principal are often confused: the principal (not principle ) reason for his departure; the plan was approved in principle (not in principal )

Commonly Confused

See principal.

Related Words

Principle, canon, rule imply something established as a standard or test, for measuring, regulating, or guiding conduct or practice. A principle is a general and fundamental truth that may be used in deciding conduct or choice: to adhere to principle. Canon, originally referring to an edict of the Church (a meaning that it still retains), is used of any principle, law, or critical standard that is officially approved, particularly in aesthetics and scholarship: canons of literary criticism. A rule, usually something adopted or enacted, is often the specific application of a principle: the golden rule.

Etymology

Origin of principle

First recorded in 1350–1400; Middle English, alteration of Middle French principe or Latin prīncipium, on the analogy of manciple; principium

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

These principles guide how scientists understand reactions and predict molecular behavior.

From Science Daily

“Britain will not yield on our principles and values about the future of Greenland under threats of tariffs,” British Prime Minister Keir Starmer said on Wednesday.

From The Wall Street Journal

"He deployed those words yesterday for the express purpose of putting pressure on me and Britain in relation to my values and principles on the future of Greenland."

From BBC

The letter also noted that staff responsible for the day-to-day supervision of detainees “appear to be inexperienced and lack basic understanding of civil detention management principles.”

From Los Angeles Times

Only the vice chairman of the Joint Chiefs would likely remain in office, and even then only to uphold the sacred principle of civilian control over the military.

From The Wall Street Journal