The Collaborative International Dictionary of English v.0.48:
Barebacked \Bare"backed`\ (b[^a]r"b[a^]kd`), a. Having the back uncovered; as, a barebacked horse. [1913 Webster]WordNet (r) 3.0 (2006):
barebacked adv 1: without a saddle; "she prefers to ride her horse bareback" [syn: bareback, barebacked] adj 1: riding without a saddle; "a bareback rider" [syn: bareback, barebacked]