Definition of "warhorse"

Just within the inner edge of the circle stood a soldier, in the military attire of a strange nation; and without it was his warhorse, in the center of a collection of mounted domestics, seemingly in readiness to undertake some distant journey.

1826, [James Fenimore Cooper], The Last of the Mohicans; a Narrative of 1757. […], volume II, Philadelphia, Pa.: H[enry] C[harles] Carey & I[saac] Lea— […]

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, A[rthur] Conan Doyle, “How a Champion Came forth from the East”, in The White Company […], volume II, London: Smith, Elder, & Co., […], pages 254–255

Among other accidents of that year was a Democratic president. Judge Atwood was a warhorse of Democracy.

1904 November, O. Henry [pseudonym; William Sydney Porter], “Cupid’s Exile Number Two”, in Cabbages and Kings, New York, N.Y.: McClure, Phillips & Co., page 93

Certainly this was a bold proposal to an old warhorse like Ecuyer, and, like a true English bulldog, he voiced a reply which made the Indians wince.

1909, Charles H. L. Johnston, Famous Indian Chiefs, Boston: L. C. Page & Company, page 188

“I don't know. I never notice much. Oh, they do kid me about not being in the army—especially the old warhorses, the old men that aren't going themselves. And this Bogart boy. And Mr. Hicks's son—he's a horrible brat. But probably he's licensed to say what he thinks about his father's hired man!”

1920, Sinclair Lewis, Main Street: The Story of Carol Kennicott, New York, N.Y.: Harcourt, Brace and Howe, page 344

Srinath: India's warhorse [title]

2002 June 2, Kashif Qamar, “Srinath: India's warhorse”, in BBC News‎

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, Millie Ryan, What Every Singer Should Know‎, Omaha, Nebr.: Franklin Publishing Co.

Les Ballets Trockadero de Monte Carlo

1997 August 6, Jennifer Dunning, “Horsing Around With Balletic Warhorses”, in The New York Times‎

A Mendelssohn Warhorse Gets the Perlman Treatment [title]

1995 August 5, Anthony Tommasini, “A Mendelssohn Warhorse Gets the Perlman Treatment”, in The New York Times‎

[…] the ROH mounts a new production of an Italian repertory warhorse that is fully on the level of the one it replaces […]

2006 June 11, Stephen Jay-Taylor, “Tosca dress”, in rec.music.opera‎ (Usenet)