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

While this might rankle a certain type of science fiction reader who expects rigorous world building and a straightforward plot, Unferth’s playfulness injects new life into some trusty old tropes that have calcified into clichés. —Literary Hub, 11 June 2026

In rigorous laboratory testing, the Blue Capacitor survived more than 60,000 charge-discharge cycles without degrading. —Mrigakshi Dixit, Interesting Engineering, 10 June 2026

This latest batch of tests involves a broader range of math problems and more rigorous protocols for its participants—to which only OpenAI and a trio of academic groups agreed. —Joseph Howlett, Scientific American, 10 June 2026

Every article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of financial products. —Liz Knueven, CNBC, 10 June 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