1. (

• degeneration ,
• devolution

) the process of declining from a higher to a lower level of effective power or vitality or essential quality ;

2. (

• degeneracy ,
• degeneration ,
• decadence ,
• decadency

) the state of being degenerate in mental or moral qualities ;

3. (

• degeneration ,
• retrogression

) passing from a more complex to a simpler biological form ;