The Collaborative International Dictionary of English v.0.48:

Reassimilate \Re`as*sim"i*late\
   (r[=e]`[a^]s*s[i^]m"[i^]*l[=a]t), v. t. & i.
   To assimilate again. -- Re`as*sim`i*la"tion
   (r[=e]`[a^]s*s[i^]m"[i^]*l[=a]"sh[u^]n), n.
   [1913 Webster]