Noah Webster's New International Dictionary of the English Language

1. (n.) Rigidity; stiffness; inflexibility.

2. (n.) A sense of chilliness, with contraction of the skin; a convulsive shuddering or tremor, as in the chill preceding a fever.

3. (n.) The becoming stiff or rigid; the state of being rigid; rigidity; stiffness; hardness.

4. (n.) See 1st Rigor, 2.

5. (n.) Severity of climate or season; inclemency; as, the rigor of the storm; the rigors of winter.

6. (n.) Stiffness of opinion or temper; rugged sternness; hardness; relentless severity; hard-heartedness; cruelty.

7. (n.) Exactness without allowance, deviation, or indulgence; strictness; as, the rigor of criticism; to execute a law with rigor; to enforce moral duties with rigor; -- opposed to lenity.

8. (n.) Severity of life; austerity; voluntary submission to pain, abstinence, or mortification.

9. (n.) Violence; force; fury.