Synonyms of arduous

arduous

adjective

ˈär-jə-wəs 

1

as in difficult

requiring considerable physical or mental effort

climbing Mount Everest is an arduous, exhausting challenge

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

2

as in challenging

requiring much time, effort, or careful attention

the arduous task of doing the research for my term paper

Synonyms & Similar Words

• challenging
• difficult
• demanding
• laborious
• tough
• onerous
• burdensome
• grueling
• hard
• toilsome
• exacting
• strenuous
• taxing
• formidable
• killing
• testing
• persnickety
• rigorous
• herculean
• oppressive
• rough
• rugged
• stringent
• stiff
• trying
• severe
• strict
• rigid
• stern

Antonyms & Near Antonyms

• light
• undemanding
• easy
• simple
• smooth
• unchallenging
• effortless
• facile
• nondemanding

Synonym Chooser

How is the word arduous different from other adjectives like it?

The words difficult and hard are common synonyms of arduous. While all three words mean "demanding great exertion or effort," arduous stresses the need of laborious and persevering exertion.

the arduous task of rebuilding

When could difficult be used to replace arduous?

While in some cases nearly identical to arduous, difficult implies the presence of obstacles to be surmounted or puzzles to be resolved and suggests the need of skill or courage.

the difficult ascent of the mountain

When is it sensible to use hard instead of arduous?

The synonyms hard and arduous are sometimes interchangeable, but hard implies the opposite of all that is easy.

farming is hard work

Example Sentences

Recent Examples of arduous

Ahead of the event, videos posted on social media show hundreds of young people making the arduous, roughly 8-kilometer (5-mile) hike up a steep mountain to reach La Citadelle, while some opted to ride horses. —ABC News, 13 Apr. 2026

Not that the itinerary is too arduous. —Anthony Lane, New Yorker, 13 Apr. 2026

Which will be an arduous task given the Heat’s recent success against the Hornets. —Roderick Boone, Charlotte Observer, 13 Apr. 2026

The transplant journey is often long and arduous. —Brittany Clayborne, USA Today, 12 Apr. 2026

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