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 credit card article is based on rigorous reporting by our team of expert writers and editors with extensive knowledge of credit card products. —Ryley Amond, CNBC, 4 Mar. 2026

This process keeps you dry during rigorous activities and cools you down. —Bestreviews, Chicago Tribune, 4 Mar. 2026

During testing, the membrane held up its thermal management properties after 1,000 hours of rigorous use. —Etiido Uko march 04, New Atlas, 4 Mar. 2026

The academy’s secondary schools — in Lincoln, Roseville and El Dorado Hills, as well as online — are known for their rigorous curriculum designed to meet or exceed UC and CSU admission requirements. —Nicole Buss, Sacbee.com, 3 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