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

Twin Metals spokesperson Kathy Graul said in a statement to the Associated Press that lifting the moratorium creates an opportunity to strengthen mineral supply chains but stressed that the company still must go through a rigorous permitting process that could last years. —Todd Richmond, Los Angeles Times, 28 Apr. 2026

Because Antler luggage comes with a lifetime warranty, every piece has to pass a rigorous 12-point testing system. —Katie Jackson, Travel + Leisure, 28 Apr. 2026

Every personal finance article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of financial products. —Kelsey Neubauer, CNBC, 28 Apr. 2026

With a rigorous and limited set of parts, Santos has kept a whole genre vital. —New York Times, 28 Apr. 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