unbacked

Short definition from Wiktionary

Adjective

1. 1
   Having no back.
2. 2
   Not supported or backed up (by someone or something).
3. 3
   Having no (or few) backers.
4. 4
   Of an animal: never having been ridden or not accustomed to being ridden; not (currently) being ridden.
5. 5
   (of a plate) Not having an antihalation backing.