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Showing results for arduous. Search instead for biduous.
Synonyms

arduous

American  
[ahr-joo-uhs, ahr-dyoo-] / ˈɑr dʒu əs, ˈɑr dyu- /

adjective

  1. requiring great exertion; laborious; difficult.

    an arduous undertaking.

    Synonyms:
    exhausting, burdensome, wearisome, onerous, toilsome, hard
    Antonyms:
    easy
  2. requiring or using much energy and vigor; strenuous.

    making an arduous effort.

  3. hard to climb; steep.

    an arduous path up the hill.

  4. hard to endure; full of hardships; severe.

    an arduous winter.


arduous British  
/ ˈɑːdjʊəs /

adjective

  1. requiring great physical or mental effort; difficult to accomplish; strenuous

  2. hard to endure; harsh

    arduous conditions

  3. hard to overcome or surmount; steep or difficult

    an arduous track

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • arduously adverb
  • arduousness noun
  • superarduous adjective
  • superarduously adverb
  • superarduousness noun
  • unarduous adjective
  • unarduously adverb
  • unarduousness noun

Etymology

Origin of arduous

First recorded in 1530–40; from Latin arduus “erect, laborious, steep”

Explanation

Use the adjective arduous to describe an activity that takes a lot of effort. Writing all those college essays and filling out the applications is an arduous process! Arduous was first used in English to mean "steep" or "difficult to climb." If you're an outdoorsman, hiking up a mountain is a lot of fun, but if you're a couch potato, it's an arduous trek. Today, the word can be used figuratively for something that is difficult or takes a lot of work. If you spend an arduous week studying for your final exams, you'll do well because you've worked really hard!

Keep Reading on Vocabulary.com

Vocabulary lists containing arduous

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Everyday cooking shouldn’t be an arduous, time-consuming task — it should be simple yet fulfilling.

From Salon • Apr. 19, 2026

Even as Gulf tanker traffic slowly resumes, the road back to normal food production will be long and arduous, given the war's impact on fertiliser supplies, the UN has warned.

From Barron's • Apr. 10, 2026

Sybilla Masters, who lived in colonial Pennsylvania, invented machinery that mechanized the time-consuming, arduous task of pounding corn by hand into usable meal or flour.

From The Wall Street Journal • Apr. 9, 2026

Acquiring security clearances remained a long and arduous process.

From MarketWatch • Apr. 4, 2026

Not that it was easy—the journey was an arduous one, perhaps harder than the sea passage to Australia.

From "Sapiens: A Brief History of Humankind" by Yuval Noah Harari