The Free On-line Dictionary of Computing (30 December 2018):

higher-order function

    (HOF) A function that can take one
   or more functions as arguments and/or return a function as
   its value.

   E.g. map in (map f l) which returns the list of results of
   applying function f to each of the elements of list l.

   A curried function is an example of a higher-order function.

   (2018-05-25)