fortuitousness vs uncertainty

fortuitousness and uncertainty both are nouns.

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

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

Other hypernyms of fortuitousness include precariousness, uncertainness.

fortuitousness (noun)	uncertainty (noun)
the quality of happening accidentally and by lucky chance	being unsettled or in doubt or dependent on chance
	the state of being unsure of something