We could do that, that is, agree on what we mean by words and list them here. Or, we could use the dictionary definitions:

https://en.wikipedia.org/wiki/Conspiracy_theory

"A conspiracy theory is an explanation for an event or situation that invokes a conspiracy by sinister and powerful groups, often political in motivation,[2][3] when other explanations are more probable.[4][5] The term has a negative connotation, implying that the appeal to a conspiracy is based on prejudice or insufficient evidence."