1. Capable of being put to use
   "usable byproducts";
   - useable
    
2. Fit or ready for use or service
   "the lawnmower is a bit rusty but still usable";
   - functional, useable, operable, operational, up and running
    
3. Convenient for use or disposal
   "2000 square feet of usable office space";
   - available, useable

See also: disposable, serviceable, useful, utile

Encyclopedia: Usable