legitimiser

Example:He was the quintessential debunker, working tirelessly to expose fraudulent practices and debilitate their legitimacy.

Definition:A person or group who undermines or disproves the legitimacy of an idea, action, or institution and reduces its authority.

Example:They were called malicious propagandists for their relentless efforts to de-legitimise the government’s claims.

Definition:Individuals or groups that spread false or misinformative information to harm or discredit an idea, action, or institution, further reducing its perceived legitimacy.