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

More rigorous radiation protection measures would be required when approaching dose limits to ensure they aren't exceeded. — ABC News, 26 July 2026

Instead, the yearly tradition continued of players talking about how formidable Bosa looked after his typically-rigorous offseason workout routine. — Chris Biderman, Sacbee.com, 26 July 2026

Through continuous research, engineering advancements, and rigorous testing, the NNPP continues to support the long-term performance of the US Navy’s nuclear capabilities, Amentum highlights. — Bojan Stojkovski, Interesting Engineering, 25 July 2026

Then again, allowing American companies to sell BPC-157 for human use could create the impression that the peptide, which hasn’t passed through the rigorous process the FDA uses to approve new drugs, nonetheless has the agency’s blessing. — Tom Bartlett, The Atlantic, 24 July 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