Also found in: Thesaurus, Legal.
1. Lacking backing or support.
2. Not having a back.
3. Never having been ridden, as a horse.
1. (of a book, chair, etc) not having a back
2. bereft of support, esp on a financial basis
3. (Horse Racing) (of a horse)
a. not supported by bets
b. never having been ridden
1. without backing or support.
2. not endorsed.
3. (of a horse) never having been ridden.