Can you explain the meaning of the term 'dynamic' in the context of programming?

In C#, the keyword dynamic is used to declare variables whose type is determined at runtime rather than at compile time. This means that the compiler does not check the type and available members of the object at compile time, and all checks and method calls happen dynamically at runtime.

Example:

dynamic obj = "Hello";
Console.WriteLine(obj.Length); // Works because the string has a Length property

obj = 123;
Console.WriteLine(obj.Length); // Runtime error because int does not have Length

Using dynamic is convenient when working with COM objects, JSON, or when the data type is unknown in advance, but it requires caution due to the lack of static type checking.