severeness vs severity

severeness and severity both are nouns.

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

As nouns, severeness and severity are synonyms defined as:

Other synonyms of severeness include austereness.

As nouns, severeness and severity are synonyms defined as:

Other synonyms of severeness include hardness, harshness, inclemency, rigor, rigorousness, rigour, rigourousness, stiffness.

As nouns, severeness and severity are synonyms defined as:

Other synonyms of severeness include asperity, grimness, hardship, rigor, rigorousness, rigour, rigourousness.

As nouns, severeness and severity are synonyms defined as:

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

Other synonyms of severeness include badness.

severeness (noun)	severity (noun)
extreme plainness	excessive sternness
excessive sternness	used of the degree of something undesirable e.g. pain or weather
something hard to endure	something hard to endure
used of the degree of something undesirable e.g. pain or weather	extreme plainness