What is Rigors?

Rigors definition and meaning on Dictionary terms:

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.