defame

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

• transitive verb To damage the reputation, character, or good name of (someone) by slander or libel. synonym: malign.
• transitive verb Archaic To disgrace.

from The Century Dictionary.

• noun Infamy; disgrace.
• To slander or calumniate, as by uttering or publishing maliciously something which tends to injure the reputation or interests of; speak evil of; dishonor by false reports.
• To charge; accuse; especially, to accuse falsely.
• To degrade; bring into disrepute; make infamous.
• Synonyms Calumniate, Slander, etc. See asperse.

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

• noun obsolete Dishonor.
• transitive verb To harm or destroy the good fame or reputation of; to disgrace; especially, to speak evil of maliciously; to dishonor by slanderous reports; to calumniate; to asperse.
• transitive verb To render infamous; to bring into disrepute.
• transitive verb rare To charge; to accuse.

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

• verb to try to diminish the reputation of.
• verb to publish a libel about.

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

• verb charge falsely or with malicious intent; attack the good name and reputation of someone