suspicion vs doubtfulness

suspicion and doubtfulness both are nouns.

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

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

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

suspicion (noun)	doubtfulness (noun)
being of a suspicious nature	uncertainty about the truth or factuality or existence of something
doubt about someone's honesty	the state of being unsure of something
an impression that something might be the case
the state of being suspected