PYTHON definition: A function pointed to by more than one "higher level" function could be a?

It's just a function. Python doesn't have (or need) "higher level functions.". Python functions are so-called "first-class objects" and names are bound to them just like variable names are to numbers, strings, lists, etc.

You can pass them as arguments or use = to store a reference to a function in a local or global variable, or in a list, tuple, set, object, etc.

(Functions have the special property of being "callable", but even that's not unique. You can define your own callable objects by adding a __call__ method to the class definition.)

I suppose you could call a Python function "higher level" if it takes another function as an argument, but that's not really a Python concept.