Synonyms of rigorous

rigorous

adjective

ˈri-g(ə-)rəs 

1

as in strict

given to exacting standards of discipline and self-restraint

a rigorous football coach who pushes his players to their physical and mental limits

Synonyms & Similar Words

• strict
• tough
• harsh
• authoritarian
• rigid
• stern
• hard
• severe
• relentless
• merciless
• hardened
• austere
• gruff
• steadfast
• demanding
• flinty
• heavy-handed
• exacting
• ramrod
• adamant
• uncompromising
• unrelenting
• pitiless
• unforgiving
• ascetic
• unsparing
• stiff
• unbending
• determined
• unyielding
• inflexible
• bullying
• hard-line
• implacable
• callous
• uncharitable
• unflinching
• monastic
• adamantine
• dour
• monkish
• immovable
• dogged
• ossified
• resolved
• obstinate
• intractable
• hard-hearted
• firm
• single-minded
• rock-ribbed
• browbeating

Antonyms & Near Antonyms

• gentle
• easy
• lax
• lenient
• indulgent
• tolerant
• mild
• kind
• easygoing
• forbearing
• soft
• undemanding
• charitable
• patient
• merciful
• accepting
• responsive
• clement
• willing
• flexible
• laid-back
• yielding
• amenable
• compliant
• agreeable
• compromising
• pliable
• softhearted
• pliant
• complaisant
• acquiescent

2

as in accurate

meeting the highest standard of accuracy

a rigorous analysis of the data

Synonyms & Similar Words

• accurate
• precise
• mathematical
• careful
• fine
• close
• exact
• strict
• correct
• refined
• delicate
• pinpoint
• spot-on
• meticulous
• definitive
• definite
• true
• subtle
• hairline
• right
• nice
• fastidious
• finicky
• finical

Antonyms & Near Antonyms

• rough
• coarse
• inaccurate
• round
• approximate
• wrong
• false
• imprecise
• incorrect
• inexact
• loose
• vague
• careless
• indefinite
• questionable
• untrue
• unclear
• doubtful
• dubious
• unreliable
• untrustworthy

3

as in stringent

not allowing for any exceptions or loosening of standards

a rigorous diet and exercise regimen

Synonyms & Similar Words

• strict
• stringent
• exacting
• rigid
• uncompromising
• meticulous
• steadfast
• conscientious
• inflexible
• hard-line
• adamant
• cast-iron
• scrupulous
• relentless
• painstaking
• punctilious
• exact
• unflinching
• stubborn
• tough
• undeviating
• brassbound
• tenacious
• close
• unbending
• harsh
• unrelenting
• determined
• dogged
• fussy
• resolved
• severe
• unsparing
• unyielding
• adamantine
• implacable
• stern
• demanding
• single-minded
• firm
• austere
• hardened
• grim
• hard
• immovable
• flinty
• unappeasable
• hard-hearted
• ironbound

Antonyms & Near Antonyms

• flexible
• lax
• loose
• relaxed
• slack
• compliant
• easy
• gentle
• mild
• pliable
• yielding
• soft
• pliant
• lenient
• acquiescent
• indulgent
• tolerant
• merciful
• easygoing
• kindly
• compromising
• negligent
• sloppy
• slipshod
• slovenly
• neglectful
• relenting
• remiss
• pampering
• spoiling
• unfussy

4

as in difficult

requiring considerable physical or mental effort

studied for umpteen months for the rigorous exam

Synonyms & Similar Words

• difficult
• challenging
• tough
• demanding
• formidable
• hard
• heavy
• complicated
• strenuous
• rugged
• rough
• arduous
• effortful
• exacting
• testing
• grueling
• severe
• laborious
• sweaty
• intricate
• tall
• exhausting
• murderous
• painful
• herculean
• backbreaking
• complex
• uphill
• toilsome
• serious
• stiff
• killer
• problematic
• strict
• hellacious
• pick-and-shovel
• elusive
• stringent
• brutal
• annoying
• abstract
• stubborn
• stressful
• involved
• oppressive
• grim
• moiling
• onerous
• Augean
• tricky
• tight
• burdensome
• abstruse
• opaque
• recondite
• thorny
• bruising
• insoluble
• troublesome
• trying
• knotty
• irksome
• labored
• hairy
• vexatious
• ticklish
• bothersome
• cruel
• spiny
• taxing
• distressing
• grievous
• inhuman

Antonyms & Near Antonyms

• simple
• easy
• light
• soft
• effortless
• cheap
• clear
• undemanding
• facile
• mindless
• elementary
• manageable
• achievable
• uncomplicated
• gentle
• doable
• smooth
• relaxed
• soothing
• comforting
• painless
• friendly
• accessible
• user-friendly
• idiotproof

Synonym Chooser

How is the word rigorous distinct from other similar adjectives?

Some common synonyms of rigorous are rigid, strict, and stringent. While all these words mean "extremely severe or stern," rigorous implies the imposition of hardship and difficulty.

the rigorous training of recruits

When can rigid be used instead of rigorous?

While in some cases nearly identical to rigorous, rigid implies uncompromising inflexibility.

rigid rules of conduct

When would strict be a good substitute for rigorous?

Although the words strict and rigorous have much in common, strict emphasizes undeviating conformity to rules, standards, or requirements.

strict enforcement of the law

When might stringent be a better fit than rigorous?

The synonyms stringent and rigorous are sometimes interchangeable, but stringent suggests severe, tight restriction or limitation.

stringent standards of admission

Example Sentences

Recent Examples of rigorous

More than 17,000 wines from 58 countries were entered into the awards, before being supped and quaffed by 245 judges in a rigorous two-week process held in London. —Maureen O'Hare, CNN Money, 17 June 2026

These schools draw families who want access to downtown amenities, cultural institutions and the airport while still prioritizing rigorous academics or a specialty focus, whether that’s language immersion, college preparation or the arts. —Lauren Jarvis-Gibson, Kansas City Star, 17 June 2026

Part of that process involved Quenda embarking on a rigorous programme of nutrition and muscle development aimed at better equipping him to handle the greater degree of physicality in Premier League football without compromising his speed or agility. —Liam Twomey, New York Times, 17 June 2026

Warraich’s hope is that by undergoing such a rigorous evaluation, the chatbot will be able to safely evaluate and treat patients without the involvement of a doctor. —Benjamin Mazer, The Atlantic, 17 June 2026