noun prin·ci·ple \ˈprin(t)-s(ə-)pəl, -sə-bəl\

: 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

Full Definition of PRINCIPLE

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
:  a primary source :  origin
a :  an underlying faculty or endowment <such principles of human nature as greed and curiosity>
b :  an ingredient (as a chemical) that exhibits or imparts a characteristic quality
capitalized Christian Science :  a divine principle :  god
in principle
:  with respect to fundamentals <prepared to accept the proposition in principle>

Usage Discussion of PRINCIPLE

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.

Examples of PRINCIPLE

  1. His investment strategy is based on the principle that the stock market offers the best returns for long-term investors.
  2. the basic principles of hydraulics
  3. Urban guerrilla warfare was futile against a thermonuclear superstate that would stop at nothing to defend the profit principle. —Philip Roth, American Pastoral, 1997


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

Rhymes with PRINCIPLE


noun prin·ci·ple \ˈprin(t)-sə-pəl\   (Medical Dictionary)

Medical Definition of PRINCIPLE

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


Next Word in the Dictionary: principledPrevious Word in the Dictionary: principiumAll Words Near: principle
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