incredulity vs uncertainty

incredulity and uncertainty both are nouns.

Word	Noun	Adjective	Verb	Adverb
incredulity	Yes	No	No	No
uncertainty	Yes	No	No	No

As nouns, uncertainty is a hypernym of incredulity; that is, uncertainty is a word with a broader meaning than incredulity:

Other hypernyms of incredulity include doubt, doubtfulness, dubiety, dubiousness, incertitude.

incredulity (noun)	uncertainty (noun)
doubt about the truth of something	being unsettled or in doubt or dependent on chance
	the state of being unsure of something