degeneration in WordNet English dictionary

1. the state of being degenerate in mental or moral qualities
   degeneracy  degeneration  decadence  decadency 
   
2. passing from a more complex to a simpler biological form
   degeneration  retrogression 
   
3. the process of declining from a higher to a lower level of effective power or vitality or essential quality
   degeneration  devolution