An axiom is a statement that everyone believes is true, such as "the only constant is change." Mathematicians use the word axiom to refer to an established proof.

The word axiom comes from a Greek word meaning “worthy.” An axiom is a worthy, established fact. For philosophers, an axiom is a statement like “something can’t be true and not be true at the same time.” An example of a mathematical axiom is “a number is equal to itself.” In everyday usage, an axiom is just a common saying, but it’s one that pretty much everyone agrees on.

Definitions of axiom
  1. noun
    (logic) a proposition that is not susceptible of proof or disproof; its truth is assumed to be self-evident
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    Euclid's axiom, Euclid's postulate, Euclidean axiom
    (mathematics) any of five axioms that are generally recognized as the basis for Euclidean geometry
    Euclid's first axiom
    a straight line can be drawn between any two points
    Euclid's second axiom
    any terminated straight line can be projected indefinitely
    Euclid's third axiom
    a circle with any radius can be drawn around any point
    Euclid's fourth axiom
    all right angles are equal
    Euclid's fifth axiom, parallel axiom
    only one line can be drawn through a point parallel to another line
    type of:
    (logic) a statement that affirms or denies something and is either true or false
  2. noun
    a saying that is widely accepted on its own merits
    synonyms: maxim
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    aphorism, apophthegm, apothegm
    a short pithy instructive saying
    a short pithy saying expressing a general truth
    a moral maxim
    Murphy's Law, Sod's Law
    humorous axiom stating that anything that can go wrong will go wrong
    type of:
    expression, locution, saying
    a word or phrase that particular people use in particular situations
Word Family

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