Chapter Right-about to Rigor of R by Webster's Dictionary (1913 Edition)

5. 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.

6. Severity of life; austerity; voluntary submission to pain, abstinence, or mortification.

The prince lived in this convent with all the rigor and austerity of a capuchin.

Addison.

7. Violence; force; fury. [Obs.]

Whose raging rigor neither steel nor brass could stay.

Spenser.

Syn. — Stiffness; rigidness; inflexibility; severity; austerity; sternness; harshness; strictness; exactness.