Dictionary definition of defamation; 1. A false accusation of an offense or a malicious misrepresentation of someone's words or actions.[Wordnet] 2. An abusive attack on a person's character or good name.[Wordnet] 3. A malicious attack.[Wordnet] 4. Act of injuring another's reputation by any slanderous communication, written or oral; the wrong of maliciously injuring the good name of another; slander; detraction; calumny; aspersion.[Websters]. An aspersion is the act of defaming or slandering someone

'Defamation' is the communication to others of a statement/claim (often through the media), that is said or implied to be true, about an individual, business, product, group, government or nation that may give a negative image. To be defined as defamation the statement has to be false. 'Aspersion' is an attack on somebody's character or reputation which could also be (but not necessarily) defamatory.