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

His intellect is evident when reviewing his rigorous course load, outstanding ACT scores, and his pursuit of the AP Capstone Diploma. —Katie Nixon, Nashville Tennessean, 3 Nov. 2025

Furthermore, the Navy’s safety culture, although rigorous, still relies on human oversight. —Christopher McFadden, Interesting Engineering, 3 Nov. 2025

The Michelin selection process is notoriously rigorous and secretive, with anonymous inspectors traveling the world to assess restaurants for quality. —Alana Al-Hatlani, Southern Living, 3 Nov. 2025

His label pioneered the industry’s intensive training system, recruiting performers as young as elementary school age and putting them through years of rigorous preparation. —Sasha Rogelberg, Fortune, 2 Nov. 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