All rigorous synonyms

adj rigorous

• precise — definitely or strictly stated, defined, or fixed: precise directions.
• uncompromising — not admitting of compromise or adjustment of differences; making no concessions; inaccessible to flexible bargaining; unyielding: an uncompromising attitude.
• onerous — burdensome, oppressive, or troublesome; causing hardship: onerous duties.
• stringent — rigorously binding or exacting; strict; severe: stringent laws.
• harsh — ungentle and unpleasant in action or effect: harsh treatment; harsh manners.
• scrupulous — having scruples, or moral or ethical standards; having or showing a strict regard for what one considers right; principled: scrupulous about defending human rights.
• meticulous — taking or showing extreme care about minute details; precise; thorough: a meticulous craftsman; meticulous personal appearance.
• brutal — A brutal act or person is cruel and violent.
• correct — If something is correct, it is in accordance with the facts and has no mistakes.
• strict — characterized by or acting in close conformity to requirements or principles: a strict observance of rituals.
• burdensome — If you describe something as burdensome, you mean it is worrying or hard to deal with.
• rigid — stiff or unyielding; not pliant or flexible; hard: a rigid strip of metal.
• proper — adapted or appropriate to the purpose or circumstances; fit; suitable: the proper time to plant strawberries.
• accurate — careful and exact
• ascetic — An ascetic person has a way of life that is simple and strict, usually because of their religious beliefs.
• austere — If you describe something as austere, you approve of its plain and simple appearance.
• bitter — In a bitter argument or conflict, people argue very angrily or fight very fiercely.
• definite — If something such as a decision or an arrangement is definite, it is firm and clear, and unlikely to be changed.
• dogmatic — relating to or of the nature of a dogma or dogmas or any strong set of principles concerning faith, morals, etc., as those laid down by a church; doctrinal: We hear dogmatic arguments from both sides of the political spectrum.
• hard — not soft; solid and firm to the touch; unyielding to pressure and impenetrable or almost impenetrable.
• inclement — (of the weather, the elements, etc.) severe, rough, or harsh; stormy.
• inflexible — not flexible; incapable of or resistant to being bent; rigid: an inflexible steel rod.
• intemperate — given to or characterized by excessive or immoderate indulgence in alcoholic beverages.
• nice — pleasing; agreeable; delightful: a nice visit.
• oppressive — burdensome, unjustly harsh, or tyrannical: an oppressive king; oppressive laws.
• punctilious — extremely attentive to punctilios; strict or exact in the observance of the formalities or amenities of conduct or actions.
• right — in accordance with what is good, proper, or just: right conduct.
• rugged — having a roughly broken, rocky, hilly, or jagged surface: rugged ground.
• stern — rear of boat
• stiff — rigid or firm; difficult or impossible to bend or flex: a stiff collar.
• ironhanded — having or governing with an iron hand.
• nonpermissive — habitually or characteristically accepting or tolerant of something, as social behavior or linguistic usage, that others might disapprove or forbid.