[ ahr-joo-uhs or, especially British, ahr-dyoo- ]
See synonyms for: arduousarduouslyarduousness on

  1. requiring great exertion; laborious; difficult: an arduous undertaking.

  2. requiring or using much energy and vigor; strenuous: making an arduous effort.

  1. hard to climb; steep: an arduous path up the hill.

  2. hard to endure; full of hardships; severe: an arduous winter.

Origin of arduous

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

Other words for arduous

Opposites for arduous

Other words from arduous

  • ar·du·ous·ly, adverb
  • ar·du·ous·ness, noun
  • su·per·ar·du·ous, adjective
  • su·per·ar·du·ous·ly, adverb
  • su·per·ar·du·ous·ness, noun
  • un·ar·du·ous, adjective
  • un·ar·du·ous·ly, adverb
  • un·ar·du·ous·ness, noun

Words Nearby arduous Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use arduous in a sentence

British Dictionary definitions for arduous


/ (ˈɑːdjʊəs) /

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

  2. hard to endure; harsh: arduous conditions

  1. hard to overcome or surmount; steep or difficult: an arduous track

Origin of arduous

C16: from Latin arduus steep, difficult

Derived forms of arduous

  • arduously, adverb
  • arduousness, noun

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