To make harsh and often false or misleading statements about.
Captain Bligh of the Bounty may be one of the most unjustly maligned figures in British naval history.
Malign is related to words like defame, slander, and libel. It implies that the person or group being maligned is the victim of false or misleading statements, but not necessarily that the maligner is guilty of deliberate lying. Something that is frequently criticized is often said to be "much maligned," which suggests that the criticism is not fair or deserved.