Rosinante (n.)

Don Quixote's horse, from Spanish Rocinante, from rocin "worn-out horse" + antes "before," "so called in allusion to the circumstance that Don Quixote's charger was formerly a wretched hack" [Klein]. Rocin is cognate with Old French rancin, roncin, ronci "draft horse, hack," but the word is of unknown origin. It was in Middle English (via Old French) as rouncy "workhorse" (c. 1300).