Definition from Wiktionary, the free dictionary
- The study of methods used in a field.
- (proscribed) A collection of methods, practices, procedures and rules used by those who work in some field.
- The implementation of such methods etc.
Usage notes 
Etymologically, methodology refers to the study of methods. Thus the use of methodology as a synonym for methods (or other simple terms such as means, technique, or procedure) is proscribed as both inaccurate and pretentious.
Derived terms 
the study of methods used in a field
a collection of methods, practices, procedures and rules used by those who work in some field