seriousness vs badness

seriousness and badness both are nouns.

Word	Noun	Adjective	Verb	Adverb
seriousness	Yes	No	No	No
badness	Yes	No	No	No

As nouns, badness is a hypernym of seriousness; that is, badness is a word with a broader meaning than seriousness:

Other hypernyms of seriousness include severeness, severity.

seriousness (noun)	badness (noun)
the trait of being serious	that which is below standard or expectations as of ethics or decency
the quality of arousing fear or distress	used of the degree of something undesirable e.g. pain or weather
an earnest and sincere feeling	an attribute of mischievous children