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

• 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

Still, state Attorney General Rob Bonta and other leaders pledged to maintain rigorous rules to ensure public safety and keep California from becoming an open-carry state. —Robert Salonga, Mercury News, 22 Sep. 2025

Every credit card review is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of credit card products. —Ryley Amond, CNBC, 20 Sep. 2025

Instead, this is about rigorous proofs found in mathematical logic via algorithmic search. —Byron Cook, Fortune, 20 Sep. 2025

Companies that fail to establish rigorous evaluation frameworks risk not only product failures but also legal liability, regulatory scrutiny and irreparable damage to user trust. —Sebastian Crossa, Forbes.com, 19 Sep. 2025

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