noun (n)

• (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)(noun.possession)

  source: wordnet30
• (genetics) a return to a normal phenotype (usually resulting from a second mutation)(noun.event)

  source: wordnet30
• a reappearance of an earlier characteristic(noun.event)

  Synonym:
  atavism, throwback
  

  source: wordnet30
• turning in the opposite direction(noun.act)

  Synonym:
  reversal, reverse, turnabout, turnaround
  

  source: wordnet30
• returning to a former state(noun.act)

  Synonym:
  regress, regression, retrogression, retroversion
  

  source: wordnet30
• a failure to maintain a higher state(noun.act)

  Synonym:
  backsliding, lapse, lapsing, relapse, relapsing, reverting
  

  source: wordnet30
• The act of returning, or coming back; return.(noun)

  source: webster1913