Rigorous
RIG'OROUS, adjective
1. Severe; allowing no abatement or mitigation; as a rigorous officer of justice.
2. Severe; exact; strict; without abatement or relaxation; as a rigorous execution of law; an enforcement of rigorous discipline.
3. Exact; strict; scrupulously accurate; as a rigorous definition or demonstration.
4. Severe; very cold; as a rigorous winter.