degenerate

Etymology

Learned borrowing from Latin dēgenerātus. Synchronically analyzable as de- + generate.

adj

1. (of qualities) Having deteriorated, degraded or fallen from normal, coherent, balanced and desirable to undesirable and typically abnormal.
   faint-hearted and degenerate king 1591, William Shakespeare, Henry VI, Part 3
   It is likely that the long evolutionary trajectory of Mycoplasma went from a reductive autotroph to oxidative heterotroph to a cell-wall–defective degenerate parasite. This evolutionary trajectory assumes the simplicity to complexity route of biogenesis, a point of view that is not universally accepted. 2013-03, Harold J. Morowitz, “The Smallest Cell”, in American Scientist, volume 101, number 2, archived from the original on 2017-01-04, page 83
2. (of a human or system) Having lost good or desirable qualities.
   As you grew more degenerate and base, I sent you millions of the croaking race 1726, Jonathan Swift, Verses on St. Patrick's Well
3. (of an encoding or function) Having multiple domain elements correspond to one element of the range.
   The genetic code is degenerate because a single amino acid can be coded by one of several codons.
4. (mathematics, of an eigenvalue) Having multiple different (linearly independent) eigenvectors.
5. (physics) Having the same quantum energy level.

noun

1. One who is degenerate, who has fallen from previous stature; an immoral or corrupt person.
   In the cult of degenerates, acts of decency, kindness and modesty could be seen as acts of apostasy.

verb

1. (intransitive) To lose good or desirable qualities.
   His condition continued to degenerate even after admission to hospital.
   Another bird quickly learned to imitate the song of a canary that was mated with it, but as the parrakeet improved in the performance the canary degenerated, and came at last to mingle the other bird's harsh chitterings with its own proper music. 1870, Shirley Hibberd, Rustic Adornments for Homes of Taste, page 170
2. (transitive) To cause to lose good or desirable qualities.