incredulity

Etymology

Attested since 1430. From Middle English incredulite, from Old French incredulité, from Late Latin incredulitas, from Latin incredulus (“unbelieving”) + -itas (“-ity”), equivalent to incredulous + -ity.

noun

1. 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. 1916, Edgar Rice Burroughs, chapter 24, in Tarzan and the Jewels of Opar
   It was a casual sneer, obviously one of a long line. There was hatred behind it, but of a quiet, chronic type, nothing new or unduly virulent, and he was taken aback by the flicker of amazed incredulity that passed over the younger man's ravaged face. 1963, Margery Allingham, chapter 8, in The China Governess
   At any other time Jessamy would have laughed at the expressions that chased each other over his freckled face: crossness left over from his struggle with the baby; incredulity; distress; and finally delight. 1967, Barbara Sleigh, Jessamy, Sevenoaks, Kent: Bloomsbury, published 1993, page 122
2. (rare) Religious disbelief, lack of faith.