rigorous

rigorous is an Adverb

Definition:

[1] 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. He shall be thrown down the Tarpeian Rock With rigorous hands. Shak. We do not connect the scattered phenomena into their rigorous unity. De Quincey.

[2] Severe; intense; inclement; as, a rigorous winter.

[3] Violent. [Obs.] "Rigorous uproar." Spenser.