reversion in WordNet English dictionary

1. a reappearance of an earlier characteristic
   atavism  reversion  throwback 
   
2. a failure to maintain a higher state
   backsliding  lapse  lapsing  relapse  relapsing  reversion  reverting 
   
3. returning to a former state
   regression  regress  reversion  retrogression  retroversion 
   
4. turning in the opposite direction
   reversion  reverse  reversal  turnabout  turnaround 
   
5. (genetics) a return to a normal phenotype (usually resulting from a second mutation)
   reversion 
   
6. (law) an interest in an estate that reverts to the grantor (or his heirs) at the end of some period (e.g., the death of the grantee)
   reversion