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

They must be matched with rigorous engineering, range safety, environmental responsibility, workforce development, financing and trusted partnerships. — Wanjiku Chebet Kanjumba, The Orlando Sentinel, 19 July 2026

For more than two decades, the duo hauled in more than 4 pounds of clams each morning from the lagoon in the Po River Delta — upending the notion that women were unsuited for such a rigorous job. — Kasha Patel, CNN Money, 18 July 2026

Where uncertainty exists, the appropriate response is not to suppress scientific debate, but to strengthen the evidence through rigorous ethical research. — Torie Bosch, STAT, 18 July 2026

Franchisors, franchisees, distributors, and food manufacturers increasingly rely upon rigorous supplier audits, product testing, traceability technology, and crisis response protocols to minimize both operational disruption and public health risks. — Gary Occhiogrosso, Forbes.com, 17 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