badness vs severeness

badness and severeness both are nouns.

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

As nouns, badness and severeness are synonyms defined as:

badness and severeness: used of the degree of something undesirable e.g. pain or weather

Other synonyms of badness include severity.

badness (noun)	severeness (noun)
that which is below standard or expectations as of ethics or decency	extreme plainness
used of the degree of something undesirable e.g. pain or weather	excessive sternness
an attribute of mischievous children	something hard to endure
	used of the degree of something undesirable e.g. pain or weather