macro Definition macro A macro is a body of text that is given a name. When the name is used in a program, it is replaced with the text to which it refers; this is called macro expansion. For example, getchar is a macro that consists of the function call getc(stdin). Because macros may employ an argument n times, any arguments that have side effects will have the side effect repeated n times as well, which may be undesirable. ***** See Also ***** #define, definitions, function, m4 COHERENT Lexicon Page 1