function object
nounA function object is a thing in a computer program that you can call like a function and also treat like an object.
In C++, a lambda expression creates a function object that can be stored in a variable.
OTHER MEANINGS
2. In mathematics, a function object is a mapping that assigns values to objects, often used in category theory.
The functor maps each object in one category to an object in another.
3. In JavaScript, a function is itself an object, so it can have properties and methods attached to it.
You can add a custom property to a JavaScript function because it is a function object.
4. A callable entity in Python that implements the __call__ method, allowing instances to be invoked like functions.
The class defines __call__, so each instance is a function object.