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

metaheuristic

    A top-level general
   strategy which guides other heuristics to search for
   feasible solutions in domains where the task is hard.

   Metaheuristics have been most generally applied to problems
   classified as NP-Hard or NP-Complete by the theory of
   computational complexity.  However, metaheuristics would
   also be applied to other combinatorial optimisation
   problems for which it is known that a polynomial-time
   solution exists but is not practical.

   Examples of metaheuristics are Tabu Search, simulated
   annealing, genetic algorithms and memetic algorithms.

   (1997-10-30)