severity

(noun) used of the degree of something undesirable e.g. pain or weather. Synonyms: badness, severeness.

(noun) something hard to endure. Synonyms: asperity, grimness, hardship, rigor, rigour, severeness, rigorousness, rigourousness. Example: "The asperity of northern winters."

(noun) extreme plainness. Synonyms: austereness, severeness.

(noun) excessive sternness. Synonyms: severeness, harshness, rigor, rigour, rigorousness, rigourousness, inclemency, hardness, stiffness. Examples: "Severity of character." "The harshness of his punishment was inhuman." "The rigors of boot camp."