I believe that is the term for recording 
additional dialogue AFTER the production is 
complete.  This is done in American animation 
when the animation doesn't match the original 
voice well, when a script change is made after 
the fact, when audio quality is poor, etc.

Also, in some shows that share production tasks 
between the US and Japan (I believe "Galaxy 
Rangers" was one such show) the initial dialogue 
is taped in the US, it is sent over to Japan to 
be animated, and then all the dialogue is re-
taped in the US to match the animation better.  

JP