Define

Define is a verb meaning to state the meaning of a term or concept, or to set the boundaries and properties that distinguish it from other things. It covers explaining what a term refers to, and specifying its scope. The word comes from Latin definire, from de- (boundaries) and finire (to end, limit). In dictionaries, to define is to give a description that captures current usage. In philosophy and logic, definitions aim to furnish necessary and sufficient conditions, and may distinguish between lexical, stipulative, precising, and theoretical definitions.

In practice, definitions vary by purpose. Lexical definitions describe existing usage; stipulative definitions assign a meaning for a term in a particular discourse; precising definitions reduce ambiguity; theoretical definitions explain a concept within a theory. Some terms in mathematics and science are defined by axioms or by set-building rules, and can be analyzed for definability and definable objects.

In programming, define often appears as a mechanism to bind a name to a value, a function, or a macro. Examples include the #define directive in C and C++, or the define forms in Lisp-family languages, where a symbol is associated with a value or function.

The act of defining is central to communication, discipline, and problem-solving, enabling precise references, reproducibility, and mutual understanding. Ambiguity in definition can lead to misinterpretation, so careful, context-appropriate definitions are valued in scholarship and practice.