1. Without braces or props
   "The unbraced shelves collapsed under the weight of the books"

1. Remove a brace or braces from
   "The orthodontist unbraced her teeth after two years"
    
2. Remove from tension
   "He unbraced the ropes holding the tent"
    
3. Undo the ties of
   "She unbraced her armour after the battle";
   - untie, unlace

See also: unsupported

Type of: relax, unbend, undo, weaken