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

Connecticut and America deserve healthcare systems that facilitate scientific research, incorporate emerging evidence and integrate the treatment options that rigorous study ultimately demonstrates to be safe and effective. — John R. Gordon, Hartford Courant, 5 July 2026

Every cybersecurity article is based on rigorous reporting by our team of expert writers and editors. — Brian Sloan, CNBC, 3 July 2026

Our rigorous benchmarking had the Swift Go 16 near the top of the pack in a variety of tests. — K. Thor Jensen, PC Magazine, 3 July 2026

First, take an assessment—a rigorous and audited behavioral profile. — Expert Panel®, Forbes.com, 2 July 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