Rigorous /(?)/

Rig·or·ous

Rigorous

a.
  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.
    We do not connect the scattered phenomena into their rigorous unity.
  2. Severe; intense; inclement; as, a rigorous winter.
  3. Violent. [Obs.]
  4. Adhering scrupulously and exactly to accepted principles; hence, logically valid; as, a rigorous proof. (Mathematics, Logic)