Steed

(n.) A horse, especially a spirited horse for state of war; -- used chiefly in poetry or stately prose.

Thesaurus Entries

Houyhnhnm, brood mare, charger, colt, courser, critter, dobbin, entire, entire horse, equine, filly, foal, gelding, horse, mare, mount, nag, prancer, stallion, stud, studhorse, tarpan, top horse, war-horse, wild horse