conspiracist
[ kuh n-spir-uh-sist ]
/ kənˈspɪr ə sɪst /
noun
a person who believes in or supports a conspiracy theory.
Also called
con·spir·a·to·ri·al·ist
[kuh n-spir-uh-tawr-ee-uh-list, ‐tohr-] /kənˌspɪr əˈtɔr i ə lɪst, ‐toʊr-/.