Source : Webster's Revised Unabridged Dictionary (1913)

Unturned \Un*turned"\, a. [Pref. un- + turned.]
   Not turned; not revolved or reversed.

   {To leave no stone unturned}, to leave nothing untried for
      accomplishing one's purpose.

            [He] left unturned no stone To make my guilt appear,
            and hide his own.                     --Dryden.

Source : WordNet®

unturned
     adj : not turned; "left no stone unturned" [ant: {turned}]