The Collaborative International Dictionary of English v.0.48:

Thereafter \There*af"ter\, adv. [AS. [eth][=ae]r[ae]fter after
   that. See There, and After.]
   1. After that; afterward.
      [1913 Webster]

   2. According to that; accordingly.
      [1913 Webster]

            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.
      [1913 Webster]

   3. Of that sort. [Obs.] "My audience is not thereafter."
      --Latimer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

thereafter
    adv 1: from that time on; "thereafter he never called again"
           [syn: thereafter, thenceforth]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "thereafter":
   after, after all, after that, afterwards, ex post facto,
   from here in, from now on, from then on, from this point,
   henceforth, henceforward, henceforwards, hereafter, hereinafter,
   in the aftermath, in the sequel, later, next, since, subsequently,
   then, thence, thenceforth, thenceforward, thenceforwards, thereon,
   thereupon, therewith