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

Sociology relies on rigorous research methods including quantitative analysis, qualitative interviews and mixed-methods designs. —Carla Cox, The Orlando Sentinel, 8 Apr. 2026

The college sold unused land in 2018 through a rigorous evaluation process. —Elizabeth Campbell, Fort Worth Star-Telegram, 8 Apr. 2026

So not sure the rigorous standard applies because someone could just kind of fake it. —Livi Stanford, Hartford Courant, 8 Apr. 2026

The researchers noted that more rigorous studies, including clinical trials, are needed to better understand whether these foods directly contribute to longer life. —Deirdre Bardolf, FOXNews.com, 8 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