degeneration

definition: passing from a more complex to a simpler biological form
example:
speech part: noun
synonyms: retrogression
definition: the process of declining from a higher to a lower level of effective power or vitality or essential quality
example:
speech part: noun
synonyms: devolution
definition: the state of being degenerate in mental or moral qualities
example:
speech part: noun
synonyms: degeneracy

How degeneration is being used?