Lewis Short
(adjective) : sellāris, e, sella
* Of or belonging to a seat (post-class.): gestatio,in a sedan,Cael. Aur. Tard. 1, 4, 92: jumenta,furnished with saddles, used for riding,Veg. 2, 28, 34; 6, 7, 5.—Subst.: sellāris, is, m., a saddlehorse, Vit. Caes. Arel. 2, 2, 20.
Charlton T. Lewis, Charles Short, A Latin Dictionary