degrade

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To reduce in grade, rank, or status; demote.
2. v. To lower in dignity; dishonor or disgrace: a scandal that degraded the participants.
3. v. To lower in moral or intellectual character; debase.
4. v. To reduce in worth or value: degrade a currency.
5. v. To impair in physical structure or function.
6. v. Geology To lower or wear by erosion or weathering.
7. v. To cause (an organic compound) to undergo degradation.
8. v. To fall below a normal state; deteriorate.
9. v. To undergo degradation; decompose: a chemical that degrades rapidly.

Century Dictionary and Cyclopedia

1. To reduce from a higher to a lower rank, degree, or type. Specifically
2. To deprive of any office or dignity; strip of honors: as, to degrade a general officer.
3. To lower in character; cause to deteriorate; lessen the value or worth of; debase: as, drunkenness degrades a man to the level of a beast.
4. In biology: To reduce in taxonomic rank; lower in the scale of classification: as, to degrade an order to the rank of a family.
5. To reduce in complexity of structure or function; simplify morphologically or physiologically: as, an organism degraded by parasitic habit.
6. In geology, to reduce in altitude or magnitude, as hills and mountains or icebergs; wear down, as by the weather.
7. In optics, to lower in position in the spectrum; increase the wave-length of (a ray of light), and hence diminish (its) refrangibility, as by the action of a fluorescent substance. See fluorescence.
8. To diminish the strength, purity, size, etc., of.
9. Synonyms and Debase, Disgrace, etc. (see abase); to dishonor, break, cashier, reduce to inferior rank. To lower, sink, impair, injure, pervert, pollute. See list under debase.
10. In natural history, to degenerate in type; pass from a higher type of structure to a lower.
11. To degenerate; become lower in character; deteriorate.
12. In a university, to take, for some particular reason, a lower degree than one is entitled to, or to avoid taking a degree at the proper or usual time; descend from a higher to a lower degree.
13. In thermodynamics, to convert from a form of greater to one of less availability: said of certain transformations of energy.

Wiktionary

1. v. transitive To lower in value or social position.
2. v. intransitive To reduce in quality or purity.

GNU Webster's 1913

1. v. To reduce from a higher to a lower rank or degree; to lower in rank; to deprive of office or dignity; to strip of honors.
2. v. To reduce in estimation, character, or reputation; to lessen the value of; to lower the physical, moral, or intellectual character of; to debase; to bring shame or contempt upon; to disgrace.
3. v. (Geol.) To reduce in altitude or magnitude, as hills and mountains; to wear down.
4. v. (Biol.) To degenerate; to pass from a higher to a lower type of structure.

WordNet 3.0

1. v. lower the grade of something; reduce its worth
2. v. reduce the level of land, as by erosion
3. v. reduce in worth or character, usually verbally