horseback, horsebacke

[Eng. horse, and back.] The back of a horse; especially that part on which the saddle is placed; generally in the phrase on horseback, that is, mounted, or riding on a horse. "There came two men on horsebacke."-Hackluyt: Voy ages , vol. ii., p. 166. horseback-riding, s. Riding on horseback. horse-bane, s. [Eng. horse , and bane .] Bot.: Enanthe phellandrium . 3. The military authorities of the War Depart under the Secretary of War. ( Eng .) horse-häir, s. & a. [Eng. horse , and hair .] A. As subst.: The hair of the manes and tails of