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

The summit push After weeks of arduous climbing, Singh led a six-man team, including Morup, Paljor and Smanla above the final camp located at 8,300 meters (27,000 feet). — Helen Regan, CNN Money, 10 Oct. 2026

The Lincoln is the second carrier that has endured an unusually long and arduous deployment to support the war against Iran and the second to receive the top unit award afterward. — ABC News, 7 Oct. 2026

The organization shared a glimpse into the arduous recovery mission on social media. — Madison E. Goldberg, PEOPLE, 2 Oct. 2026

The Washington is typically deployed to Pacific Ocean but it was moved to the Middle East to relieve the USS Abraham Lincoln, whose arduous deployment resulted in the crew being at sea for more than 260 days straight. — Konstantin Toropin, Los Angeles Times, 1 Oct. 2026

Podcast

Get Word of the Day delivered to your inbox!