severity vs badness

severity and badness both are nouns.

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

As nouns, severity and badness are synonyms defined as:

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

Other synonyms of severity include severeness.

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