peradventure vs doubtfulness

peradventure and doubtfulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
peradventure	Yes	No	No	Yes
doubtfulness	Yes	No	No	No

As nouns, doubtfulness is a hypernym of peradventure; that is, doubtfulness is a word with a broader meaning than peradventure:

Other hypernyms of peradventure include doubt, dubiety, dubiousness, incertitude, uncertainty.

peradventure (noun)	doubtfulness (noun)
doubt or uncertainty as to whether something is the case	uncertainty about the truth or factuality or existence of something
	the state of being unsure of something

peradventure (adverb)	doubtfulness (adverb)
by chance