WordWeb Online

1. Not made more desirable or valuable or profitable; especially not made ready for use or marketing
   "taxes on unimproved land are low"; "unimproved dirt roads"
    
2. (of land) not cleared of trees and brush; in the wild or natural state
   "a farm with 50 acres of unimproved and 68 acres of improved land"; "unimproved woodlands"

See also: dirt, scrub, uncleared, ungraded

Antonym: improved

Encyclopedia: Unimproved