Definition - What does Anonymous Method mean?
An anonymous method is a a function or subroutine that is defined or called without being name-bound to an identifier.
Anonymous methods are used by many modern programming languages such as C#, and PHP.
Anonymous methods are more commonly known as anonymous functions.
Techopedia explains Anonymous Method
Anonymous methods derive from mathematics that dates back to the 1930s when Alonzo Church invented the lambda-calculus, the inspiration for functional programming which came much later. The first programming language to contain these types of functions was LISP in 1958.
The idea of anonymous methods is that a routine can have functions that exist within code blocks that can operate internally within that block of code and make computations whose purpose is usually to pass arguments to higher order functions, commonly found in languages that have first-class functions.
Anonymous classes are used in other languages such as Java which does not support anonymous methods.