Source : WordNet®

warhorse
     n 1: a work of art (composition or drama) that is part of the
          standard repertory but has become hackneyed from much
          repetition
     2: an experienced person who has been through many battles;
        someone who has given long service [syn: {veteran}, {old-timer},
         {oldtimer}, {old hand}, {old stager}, {stager}]
     3: horse used in war