rigorous

adjective

rig·​or·​ous ˈri-g(ə-)rəs 

1

: manifesting, exercising, or favoring rigor : very strict

2

a

: marked by extremes of temperature or climate

b

: harsh, severe

3

: scrupulously accurate : precise

rigorously adverb

rigorousness noun

Synonyms of rigorous

• strict
• tough
• harsh
• authoritarian
• rigid
• stern

Choose the Right Synonym for rigorous

rigid, rigorous, strict, stringent mean extremely severe or stern.

rigid implies uncompromising inflexibility.

rigid rules of conduct

rigorous implies the imposition of hardship and difficulty.

the rigorous training of recruits

strict emphasizes undeviating conformity to rules, standards, or requirements.

strict enforcement of the law

stringent suggests severe, tight restriction or limitation.

stringent standards of admission

Examples of rigorous in a Sentence

rigorous enforcement of the rules

a rigorous course of study

We subjected the data to a rigorous analysis.

Recent Examples on the Web

Warren's students were under a rigorous program, Knox said. —Everett Eaton, jsonline.com, 10 Feb. 2026

Through a rigorous multibarrier treatment process, the system produces drinking water that meets or exceeds all state and federal standards and is indistinguishable in quality from Aurora’s traditional mountain water supplies. —Mike Coffman, Denver Post, 10 Feb. 2026

The two have a natural connection shaped by rigorous daily practice sessions. —Patrick Z. McGavin, Chicago Tribune, 10 Feb. 2026

Every savings article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of banking and savings products. —Jasmin Suknanan, CNBC, 10 Feb. 2026

Word History

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for rigorous

• vigorous

Kids Definition

rigorous

adjective

rig·​or·​ous ˈrig-(ə-)rəs 

1

: very strict

2

: marked by great differences of temperature or climate

3

: very accurate

rigorously adverb

rigorousness noun