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

As a result, countries typically have rigorous regulations around mining, making the process much harder to navigate. —Jasmine Laws, MSNBC Newsweek, 13 Oct. 2025

Every small business insurance review is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of small business insurance products. —Jasmin Suknanan, CNBC, 13 Oct. 2025

Here’s how all four teams look heading into their Championship Series, along with some rigorous, confident analysis for each team. —Grant Brisbee, New York Times, 12 Oct. 2025

Whereas degree programs have to go through rigorous faculty and administrative oversight, which can take years, non-degree programs don’t require the same kind of oversight. —Chris Quintana, USA Today, 12 Oct. 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