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

While the results were impressive, the fact that Nutrafol even went to the trouble of creating such a rigorous study around its supplement was enough to make our dermatologist judges suspend their usual skepticism around the ingestibles category. —Megan McIntyre, Allure, 16 Sep. 2025

To ensure a smooth transition, the team added an additional six months to the initial timeline for rigorous testing. —Brian Wasson, Forbes.com, 15 Sep. 2025

Every credit card article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of credit card products. —Jason Stauffer, CNBC, 15 Sep. 2025

Other times it’s used in a more specific and technical way, to signify an irreversible bifurcation that has a rigorous mathematical definition. —Gregory Barber, Quanta Magazine, 15 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