warhorse

noun3

1. •
   (historical) Any horse used in horse-cavalry, but especially one bearing an armoured knight.

   • As he spoke, the knight-errant, who had remounted his war-horse, galloped forward to the royal stand, with a silken kerchief bound round his wounded arm. — 1891
2. •
   (informal, figurative) An experienced person who has been through many battles, situations or contests; someone who has given long service.

   • Among other accidents of that year was a Democratic president. Judge Atwood was a warhorse of Democracy. — 1904
3. •
   A regularly revived theatrical or musical work, as with Hamlet or a Beethoven symphony, or as excerpts thereto. May imply that the work in question has become hackneyed.

   • I remember taking the old warhorse, “Una Voce Poco Fa,” from Il Barbiere (Rossini) to three of the greatest living singing masters in Italy. — 1910