Lewis Short
(adjective) : dorsŭālis, e, dorsum
* Of or on the back, dorsal (post-class): notae equi,App. M. 11, p. 266, 32; cf.: crustae ferarum,Amm. 22, 15; and, pinnae,Sol. 12.—Subst.: dorsualia, ium, n., a cover for the back of beasts, Trebell. Gallien. 8.
Charlton T. Lewis, Charles Short, A Latin Dictionary