noun /ˌɪn.kɹəˈdjuːl.ɪ.ti/
a) Unwillingness or inability to believe; doubt about the truth or verisimilitude of something; disbelief.
Wide went her eyes in wonder and incredulity, as she beheld this seeming apparition risen from the dead.
b) Religious disbelief, lack of faith.
See Also: incredibility, incredulous
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