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

So Republicans are looking to get parts of it through the arduous reconciliation process that allows both chambers to pass a bill with a simple majority. — Kevin Freking, Fortune, 15 July 2026

In March, Melissa Graybill, 52, watched her mother, who is 69, begin an arduous recovery journey after tripping while getting off a horse. — Erica Sloan, Washington Post, 14 July 2026

But its insistence on seeing the birth of a nation as a dangerous endeavor requiring persistent, even arduous, generosity proves enchanting. — Ben Travers, IndieWire, 9 July 2026

In the weeks since, teams have been clearing the Cape Canaveral launch site of debris and beginning the arduous process of rebuilding. — Eric Lagatta, USA Today, 8 July 2026

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