What are the method heading and the body combined referred to as?

The combination of the method heading and the body is aptly referred to as the definition of the method. The method heading includes the method's name, its return type, and any parameters it may take, while the body contains the block of code that defines what the method does when called. Together, these elements encapsulate the full characterization of a method, making it possible for other parts of the program to call and execute the functionality provided by that method.

In contrast, the term "method call" refers to the act of invoking the method to perform its task. The "method prototype" generally refers only to the declaration of a method (including its name and parameters) without its body, and "the function" is a broader term that can refer to any callable piece of code, whether in Java or other programming languages. Thus, the most accurate term for the entirety of the method's functionality is indeed the definition of the method.