The Collaborative International Dictionary of English v.0.48:

Reaffirmance \Re`af*firm"ance\ (r[=e]`[a^]f*f[~e]rm"ans),
Reaffirmation \Re*af`fir*ma"tion\
   (r[=e]*[a^]f`f[~e]r*m[=a]"sh[u^]n), n.
   A second affirmation.
   [1913 Webster] re-afforest

WordNet (r) 3.0 (2006):

reaffirmation
    n 1: renewed affirmation [syn: reassertion, reaffirmation]