Merriam-Webster Collegiate Dictionary   

1  heu-ris-tic
Pronunciation: hyu-'ris-tik
Function: adjective
Etymology: German heuristisch, from New Latin heuristicus, from Greek heuriskein to discover; akin to Old Irish fo-fúair he found
Date: 1821
: involving or serving as an aid to learning, discovery, or problem-solving by experimental and especially trial-and-error methods ; also : of or relating to exploratory problem-solving techniques that utilize self-educating techniques (as the evaluation of feedback) to improve performance

2  heuristic
Function: noun
Date: 1860
  1 : the study or practice of heuristic procedure
  2 : heuristic argument
  3 : a heuristic method or procedure