Quick Definition
Arduous (adjective) describes a task, journey, or process that is difficult and tiring, demanding a great deal of sustained physical or mental effort.
Example: "The climb to the summit was long and arduous."
What Does Arduous Mean?
The word arduous comes from the Latin arduus, meaning "steep" or "high," and so "hard to climb." It entered English in the 16th century. The original image of a steep, exhausting climb still lies behind the modern meaning: anything arduous wears you down through prolonged, demanding effort.
In modern English, arduous describes work, journeys, training, or processes that are not just hard but also tiring and drawn out. It is a formal, somewhat literary word. You will often meet it in the fixed phrase "long and arduous," as in "a long and arduous journey" or "a long and arduous process of reform."
Key point: arduous combines two ideas — difficulty and exhaustion over time. A quick, sharp challenge is "difficult"; a slow, draining one that leaves you worn out is "arduous." This is what makes it stronger and more vivid than everyday words like "hard."
Example Sentences
| Sentence | Level / Note |
|---|---|
| The climb to the summit was long and arduous. | B2/C1 — travel / neutral register |
| Training for the marathon proved more arduous than she had expected. | C1 — sport / character description |
| After an arduous day in the fields, the workers slept deeply. | C1 — narrative / literary register |
| The peace talks were arduous, dragging on for many months. | C1 — politics / journalism |
| Editing the thousand-page manuscript was an arduous but rewarding task. | C1 — formal / academic register |
Word Family
Adjective
arduous
"An arduous journey."
Adverb
arduously
"They worked arduously."
Noun (rare)
arduousness
"The arduousness of the task."
No verb form
—
Say: "a long and arduous road."
Synonyms & Antonyms
Synonyms
- gruelling — extremely tiring and demanding
- strenuous — requiring great physical effort
- laborious — requiring long, hard work
- taxing — demanding and draining
- exhausting — making you very tired
Antonyms
- easy — needing little effort
- effortless — achieved without any effort
- simple — not complicated
- undemanding — requiring little effort
- light — not heavy or tiring
Common Collocations
- an arduous journey / trek — "They survived an arduous journey across the desert."
- an arduous task — "Sorting the records was an arduous task."
- an arduous climb — "The arduous climb took six hours."
- an arduous process — "Reform proved a slow and arduous process."
- long and arduous — "It was a long and arduous campaign."
- arduous training / negotiations — "The talks were arduous and tense."
Related Words
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Frequently Asked Questions about “arduous”
What does arduous mean in English?
Arduous means difficult and tiring, requiring a great deal of sustained physical or mental effort. An arduous task, journey, or process is hard work that leaves you exhausted. For example: 'The climb to the summit was long and arduous.' It is a formal word, often used to describe demanding journeys, training, negotiations, or any process that takes prolonged effort.
How do you pronounce arduous?
Arduous is pronounced /ˈɑːdjuəs/ in British English. It has three syllables: AR-dyoo-uhs. The main stress falls on the first syllable: AR. The first vowel is a long 'ah' sound, with no 'r' pronounced in standard British English. Say it slowly: AR... dyoo... uhs. In American English it is often /ˈɑːrdʒuəs/.
What is the CEFR level of arduous?
Arduous is a C1 (Advanced) level word. It appears in journalism, literature, formal writing, and descriptions of demanding tasks or journeys. C1 learners are expected to use vivid adjectives like arduous to describe difficulty and exhaustion, rather than only basic words such as 'hard' or 'difficult'.
What are synonyms for arduous?
Synonyms for arduous include: gruelling (extremely tiring and demanding), strenuous (requiring great physical effort), laborious (requiring long, hard work), taxing (demanding and draining), and exhausting (making you very tired). Arduous especially stresses that the difficulty continues over a long period and wears you down.
What are antonyms of arduous?
Antonyms of arduous include: easy (needing little effort), effortless (achieved without any effort), simple (not complicated), undemanding (requiring little effort or attention), and light (not heavy or tiring). You might contrast: 'After the arduous mountain ascent, the gentle, effortless walk back down felt like a holiday.'
What is the adverb form of arduous?
The adverb is arduously (/ˈɑːdjuəsli/): 'They worked arduously through the night to repair the bridge.' The noun is arduousness, though it is rare — most writers prefer phrases like 'the difficulty of the task' instead. There is no verb form. The adjective arduous is by far the most common form.
What are common collocations with arduous?
Common collocations with arduous include: an arduous journey, an arduous task, an arduous climb, an arduous process, arduous training, an arduous trek, a long and arduous road, and arduous negotiations. The pattern 'long and arduous' is especially common, emphasising both the duration and the difficulty.
What is the difference between arduous and difficult?
Difficult is a general word meaning hard to do. Arduous is stronger and more specific: it stresses that something is not only difficult but also physically or mentally tiring and lasts a long time. A maths problem can be difficult; a week-long mountain expedition is arduous. Arduous is also more formal and is often used about journeys, training, and long processes.
Can arduous describe both physical and mental effort?
Yes. Arduous originally described steep, hard climbs, so it is strongly associated with physical effort — 'an arduous trek'. But it is also used for demanding mental or procedural effort: 'arduous negotiations', 'an arduous legal process', or 'the arduous task of editing the manuscript'. In every case it suggests prolonged, tiring effort that wears the person down.
How can I practise the word arduous on LexFizz?
Use LexFizz's Flash Cards to practise arduous alongside related C1 adjectives like gruelling and strenuous. The Vocabulary Quiz presents arduous in context so you understand how it differs from 'difficult', and the Wordsearch helps you fix the tricky 'duous' spelling. Try writing two sentences: one about an arduous journey and one about an arduous process at work.