Defamation—also called calumny, vilification, traducement, slander (for transitory statements), and libel (for written, broadcast, or otherwise published words)—is the communication of a statement that makes a claim, expressly stated or implied to be factual, that may give an individual, business, product, group, government, or nation a negative image. This can be also any disparaging statement made by one person about another, which is communicated or published, whether true or false, depending on legal state. In Common Law it is usually a requirement that this claim be false and that the publication is communicated to someone other than the person defamed (the claimant).

In common law jurisdictions, slander refers to a malicious, false,^{[not specific enough to verify]} and defamatory spoken statement or report, while libel refers to any other form of communication such as written words or images. Most jurisdictions allow legal actions, civil and/or criminal, to deter various kinds of defamation and retaliate against groundless criticism. Related to defamation is public disclosure of private facts, which arises where one person reveals information that is not of public concern, and the release of which would offend a reasonable person. "Unlike [with] libel, truth is not a defense for invasion of privacy."^{[not verified in body]}