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

An arduous journey Pearson pitched four seasons with the Blue Jays. — Kansas City Star, 3 Sep. 2026

The journey back to the river camp was an arduous three-mile hike over rough terrain. — Jan Thacker, Outdoor Life, 3 Sep. 2026

Get a first glimpse of the young royals and the travelers on their arduous journey right here. — Georg Szalai, HollywoodReporter, 2 Sep. 2026

Shasta, the fifth-highest peak in California, can be ascended by routes that don’t require technical climbing skills, but all are arduous hikes. — Bay Area News Group, Mercury News, 2 Sep. 2026

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