Definition:Definition

Definition
A definition lays down the meaning of a concept.

It is a statement which tells the reader what something is.

It can be understood as an equation in (usually) natural language.

Some authors distinguish between particular types of definition, particularly of symbols:

Stipulative Definition
A stipulative definition is a definition which defines how to interpret the meaning of a symbol.

It stipulates, or lays down, the meaning of a symbol in terms of previously defined symbols or concepts.

Ostensive Definition
An ostensive definition is a definition which shows what a symbol is, rather than use words to explain what it is or what it does.

As an example of an ostensive definition, we offer up:


 * The symbol used for a stipulative definition is:
 * $\text {(the symbol being defined)} \ := \ \text {(the meaning of that symbol)}$

Alternatively:
 * The symbol used for a stipulative definition is:
 * $\text {(the symbol being defined)} \ \stackrel {\mathbf {def}} {=\!=} \ \text {(the meaning of that symbol)}$

... although this latter construct is deprecated through being old-fashioned and awkward to reproduce.

Also see

 * Undefined Term
 * Circular definition

You can't get much more circular than defining the definition of definition.