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

What follows is just a sampling of the stories NPR staff believe made some of the deepest ripples this year — reminders of what rigorous, compassionate journalism can do, and why the work remains as urgent as ever. —Thomas Evans, NPR, 22 Dec. 2025

Our commitment to fair, rigorous reporting—and to applying pressure to power—remains as strong as ever. —David Remnick, New Yorker, 22 Dec. 2025

Every small business article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of small business products. —Jasmin Suknanan, CNBC, 21 Dec. 2025

But after an eight-month iteration period in 2024, Shield AI’s V-BAT cleared rigorous Ukrainian jamming tests. —Jessica Mathews, Fortune, 21 Dec. 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