degenerate

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Having declined, as in function or nature, from a former or original state.
• adjective Morally corrupt or given to vice.
• adjective Physics Relating to two or more quantum states that share the same quantum numbers.
• adjective Physics Characterized by great density and consisting of atoms stripped of electrons.
• adjective Medicine Characterized by degeneration, as of tissue, a cell, or an organ.
• adjective Biology Having lost one or more highly developed functions, characteristics, or structures through evolution.
• adjective Genetics Relating to or being a gene that has multiple codons for the same amino acid.
• noun A depraved or corrupt person.
• intransitive verb To fall below a normal or desirable state, especially functionally or morally; deteriorate.
• intransitive verb To decline in quality.
• intransitive verb To undergo degeneration.

from The Century Dictionary.

• To lose, or become impaired with respect to, the qualities proper to the race or kind, or to a prototype; become of a lower type.
• Specifically To decay in quality; pass to an inferior or a worse state; suffer a decline in character or constitution; deteriorate.
• Synonyms To deteriorate, decline.
• Having lost, or become impaired with respect to, the qualities proper to the race or kind; having been reduced to a lower type.
• Specifically Having fallen into a less excellent or a worse state; having declined in physical or moral qualities; deteriorated; degraded.
• Characterized by or associated with degeneracy; unworthy; debased: applied to inanimate objects.
• noun One who has retrograded from a normal type or standard, especially in moral nature and character, and exhibits certain morbid physical and mental traits and tendencies.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To be or grow worse than one's kind, or than one was originally; hence, to be inferior; to grow poorer, meaner, or more vicious; to decline in good qualities; to deteriorate.
• intransitive verb (Biol.) To fall off from the normal quality or the healthy structure of its kind; to become of a lower type.
• adjective Having become worse than one's kind, or one's former state; having declined in worth; having lost in goodness; deteriorated; degraded; unworthy; base; low.
• noun a person who has declined from a high standard, especially a sexual deviate; -- usually used disparagingly or opprobriously of persons whose sexual behavior does not conform to the norms of accepted morals.
• noun a person or thing that has fallen from a higher to a lower state, or reverted to an earlier type or stage of development or culture.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective having deteriorated, degraded or fallen from normal, coherent, balanced and desirable to an undesirable and typically abnormal
• adjective having lost good or desirable qualities
• adjective having multiple domain elements correspond to one element of the range
• adjective mathematics a degenerate case is a limiting case in which a class of object changes its nature so as to belong to another, usually simpler, class.
• adjective physics Having the same quantum energy level
• noun One is degenerate, who has fallen from previous stature.
• verb intransitive (of humans or systems) to lose good or desirable qualities;

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb grow worse
• adjective unrestrained by convention or morality
• noun a person whose behavior deviates from what is acceptable especially in sexual behavior