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

Every personal finance article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of financial products. —Ryley Amond,jason Stauffer, CNBC, 17 Mar. 2026

To remove stains, Sessums recommends rigorous spot cleaning. —Nashia Baker, Architectural Digest, 17 Mar. 2026

The luxury wellness retreat is known for its rigorous, multi-day programs centered on hiking, nutrition, and mindfulness. —Samantha Leal, Travel + Leisure, 16 Mar. 2026

Amid geopolitical realignment, rapid technological change, and market volatility, the annual convening centers on rigorous reporting and candid dialogue about the decisions shaping global growth. —Rachel Oppenheim, semafor.com, 16 Mar. 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