Available Definitions:
1) a. - Manifesting, exercising, or favoring rigor; allowing no abatement or mitigation; scrupulously accurate; exact; strict; severe; relentless; as, a rigorous officer of justice; a rigorous execution of law; a rigorous definition or demonstration.
2) a. - Severe; intense; inclement; as, a rigorous winter.
3) a. - Violent.