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

The club agreed to a rigorous trial period over the course of several months during the 2024-25 season, ending with Biolyz signing the Dortmund to its first commercial contract. — Justin Birnbaum, Sportico.com, 10 Aug. 2026

These are precisely the capacities a rigorous liberal arts education is built to develop. — Dr. Alan Kadish, New York Daily News, 9 Aug. 2026

Here’s What That Means Before acquiring weapons, the military requires multiple rounds of rigorous testing to ensure that the weapons are battle-ready. — Rebecca Schneid, Time, 8 Aug. 2026

Cristo Rey students combine rigorous college-preparatory coursework with meaningful professional work experience, graduating with both academic knowledge and workplace skills that prepare them for what comes next. — Lisa Schade, Forbes.com, 7 Aug. 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