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
demanding strict attention to rules and procedures; "rigorous discipline"; "tight security"; "stringent safety measures" rigidly accurate; allowing no deviation from a standard; "rigorous application of the law"; "a strict vegetarian
A test, system, or procedure that is rigorous is very thorough and strict. The selection process is based on rigorous tests of competence and experience. + rigorously rig·or·ous·ly rigorously conducted research
used of circumstances (especially weather) that cause suffering; "brutal weather"; "northern winters can be cruel"; "a cruel world"; "a harsh climate"; "a rigorous climate"; "unkind winters"