A definition assigns properties to some sort of mathematical object. For example, Euclid's *Elements* starts with a number of definitions, such as "a line
is a breadthless length." After definitions, Euclid gives postulates
or axioms. Based on these, he provides a number of proofs
and constructions.

# Definition

## See also

Axiom, Postulate, Proof## Explore with Wolfram|Alpha

## Cite this as:

Weisstein, Eric W. "Definition." From
*MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/Definition.html