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

Those drugs undergo a rigorous application process involving three phases of trials that usually take nearly a decade to complete. — Andrew Yockey, Fortune, 15 Oct. 2026

The program will combine rigorous coursework and mentorship opportunities with hands-on teaching placements in diverse urban, suburban and rural K-12 districts in the Sacramento region, according to its website. — Tarini Mehta, Sacbee.com, 15 Oct. 2026

But the ones at issue here haven’t gone through that rigorous vetting process. — ABC News, 15 Oct. 2026

Hyman said the field’s credibility would depend on rigorous research, responsible marketing, and long-term safety monitoring. — Meghana Keshavan, STAT, 15 Oct. 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