harshness, sternness, or rigor

Their lives were marked by severity.

austere simplicity, as of style, manner, or taste

The severity of the decor was striking.

intensity or sharpness, as of cold or pain.

grievousness; hard or trying character or effect

The severity of his loss was finally becoming apparent.

rigid exactness or accuracy.

an instance of strict or severe behavior, punishment, etc.

noun

austerity , hardness , harshness , rigidity , rigor , rigorousness , sternness , strictness , stringency , toughness , depth , ferociousness , ferocity , fierceness , fury , pitch , vehemence , vehemency , violence