degenerate

1 :  to pass from a higher to a lower type or condition :  deteriorate her fixed mysterious smile degenerated into a fatuous stare — J. C. Powys

2 :  to sink into a low intellectual or moral state The debate degenerated into a shouting match. At the same time, discotheques degenerated into seedier venues … —shifty, often Mob-run last-martini stops for business commuters … — Peter Braunstein

3 :  to decline in quality the poetry gradually degenerates into jingles … the sitcom has degenerated into a sparring ring of personal insult — James Wolcott

4 biology :  to decline from a condition or from the standards of a species, race, or breed

5 biology :  to evolve or develop into a less autonomous (see autonomous 2a) or less functionally active form degenerated into dependent parasites

:  to cause to degenerate

:  one that is degenerate (see ¹degenerate) : such asa :  one degraded from the normal moral standard social degeneratesb :  a sexual pervertc anthropology :  one showing signs of reversion (see reversion 3a) to an earlier culture stage

1a:  having declined (as in nature, character, structure, or function) from an ancestral or former state; especially :  having deteriorated progressively (as in the process of evolution) especially through loss of structure and functionb:  having sunk to a lower and usually corrupt and vicious state

2:  having more than one codon representing an amino acid; also :  being such a codon

1:  to sink into a low intellectual or moral state

2:  to pass from a higher to a lower type or condition: asa:  to gradually deteriorate so that normal function or structure is impaired or lost the retina degeneratedb:  to decline from the standards of a species, race, or breed

3:  to evolve or develop into a less autonomous or less functionally active form degenerated into dependent parasites

:  one that is degenerate: asa:  one degraded from the normal moral standardb:  a sexual pervert