arduous
/ˈɑɹ.d͡ʒu.əs/adjective
arduous is spelled A-R-D-U-O-U-S: 7 letters and 3 syllables. It appears 1.5 times per million words in written English, the 22,965th most frequent word form (wordfreq, 2021 data). As an adjective, arduous means “Needing or using up much energy; testing powers of endurance” (English Wiktionary, September 2026).
How many letters and syllables are in arduous?
| Letters | 7: A-R-D-U-O-U-S |
|---|---|
| Syllables | 3 (from its American pronunciation) |
| In writing | 1.5 times per million words; the 22,965th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is arduous?
Arduous appears 1.5 times per million words in written English, the 22,965th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce arduous?
- UK /ˈɑː.djʊ.əs/
- UK /ˈɑː.d͡ʒʊ.əs/
- US /ˈɑɹ.d͡ʒu.əs/
Arduous has 3 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-arduous.ogg, Wikimedia Commons (author and licence on each file's page).
Forms of arduous
- more arduous comparative
- most arduous superlative
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does arduous mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
Needing or using up much energy; testing powers of endurance.
The movement towards a peaceful settlement has been a long and arduous political struggle.
- 2
obsoleteburning; ardent
- 3
Difficult or exhausting to traverse.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Arduous in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| French | ardu |
| German | mühsam, anstrengend, beschwerlich, erschöpfend , steil |
| Portuguese | árduo |
| Spanish | arduo, riguroso, dispendioso |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does arduous come from?
From Latin arduus (“lofty, high, steep, hard to reach, difficult, laborious”), akin to Irish ard (“high”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).