truther
This term is heavily laden with irony and sarcasm. While the user of the word "truther" often views themselves as a seeker of hidden facts, the term is predominantly used by outsiders, journalists, and skeptics to categorize individuals who adhere to conspiracy theories. It carries a strong connotation of delusion or stubbornness in the face of empirical evidence.
In a socio-political context, the word is almost always used pejoratively. It suggests a specific psychological profile: someone who rejects institutional authority and believes in a secret, malevolent orchestration of events. Because it is a modern neologism born from internet culture, it is unsuitable for formal academic or legal writing unless the writer is specifically discussing the sociology of conspiracy movements.