Source : Webster's Revised Unabridged Dictionary (1913)

Reinstatement \Re`in*state"ment\ (-ment), n.
   The act of reinstating; the state of being reinstated;
   re?stablishment.

Source : WordNet®

reinstatement
     n 1: the condition of being reinstated; "her reinstatement to her
          former office followed quickly"
     2: the act of restoring someone to a previous position; "we
        insisted on the reinstatement of the colonel"