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.
Severe; intense; inclement; as, a rigorous winter.
rigorous in Dutch is streng, wettisch, gestreng, strikt
rigorous in Finnish is ankara
rigorous in French is rigoureux
rigorous in German is hart, hart, streng
rigorous in Italian is severo
rigorous in Spanish is riguroso