degeneration

英[dɪ,dʒenə'reɪʃ(ə)n] 美[dɪ,dʒɛnə'reʃən]

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

2. the state of being degenerate in mental or moral qualities

3. passing from a more complex to a simpler biological form