The Collaborative International Dictionary of English v.0.48:
Unbacked \Un*backed"\, a. 1. Never mounted by a rider; unbroken. "Unbacked colts." --Shak. [1913 Webster] 2. Not supported or encouraged; not countenanced; unaided. --Daniel. [1913 Webster]WordNet (r) 3.0 (2006):
unbacked adj 1: unsupported by other people [syn: single-handed, unassisted, unbacked]