strictness, severity, or harshness, as in dealing with people.

the full or extreme severity of laws, rules, etc.

severity of living conditions; hardship; austerity

the rigor of wartime existence.

a severe or harsh act, circumstance, etc.

scrupulous or inflexible accuracy or adherence

the logical rigor of mathematics.

severity of weather or climate or an instance of this

the rigors of winter.

Pathology . a sudden coldness, as that preceding certain fevers; chill.

Physiology . a state of rigidity in muscle tissues during which they are unable to respond to stimuli due to the coagulation of muscle protein.

Obsolete . stiffness or rigidity.

noun

ease , elasticity , flexibility , leniency , pliability

noun

accuracy , affliction , asperity , austerity , conscientiousness , conventionalism , difficulty , exactitude , firmness , hardness , hardship , harshness , inclemency , inflexibility , intolerance , meticulousness , obduracy , ordeal , preciseness , precision , privation , punctiliousness , rigidity , roughness , severity , sternness , stiffness , stringency , suffering , tenacity , thoroughness , traditionalism , trial , tribulation , vicissitude , visitation , rigorousness , strictness , toughness , ardor , cruelty , exactness , fury , scrupulosity , sharpness , strenuosity