SEVERENESS
severity, severeness, harshness, rigor, rigour, rigorousness, rigourousness, inclemency, hardness, stiffness
(noun) excessive sternness; “severity of character”; “the harshness of his punishment was inhuman”; “the rigors of boot camp”
austereness, severity, severeness
(noun) extreme plainness
asperity, grimness, hardship, rigor, rigour, severity, severeness, rigorousness, rigourousness
(noun) something hard to endure; “the asperity of northern winters”
badness, severity, severeness
(noun) used of the degree of something undesirable e.g. pain or weather
Source: WordNet® 3.1
Etymology
Noun
severeness (usually uncountable, plural severenesses)
The property of being severe.
Source: Wiktionary