Source : Webster's Revised Unabridged Dictionary (1913)

Thereafter \There*af"ter\, adv. [AS. [eth][=ae]r[ae]fter after
   that. See {There}, and {After}.]
   1. After that; afterward.

   2. According to that; accordingly.

            I deny not but that it is of greatest concernment in
            the church and commonwealth to have a vigilant eye
            how books demean themselves as well as men; and
            thereafter to confine, imprison, and do sharpest
            justice on them as malefactors.       --Milton.

   3. Of that sort. [Obs.] ``My audience is not thereafter.''
      --Latimer.

Source : WordNet®

thereafter
     adv : from that time on; "thereafter he never called again" [syn:
           {thenceforth}]