incredulity vs mental rejection

incredulity and mental rejection both are nouns.

Word	Noun	Adjective	Verb	Adverb
incredulity	Yes	No	No	No
mental rejection	Yes	No	No	No

As nouns, incredulity and mental rejection are synonyms defined as:

Other synonyms of incredulity include disbelief, scepticism, skepticism.

incredulity (noun)	mental rejection (noun)
doubt about the truth of something	doubt about the truth of something