arduous

/ˈɑɹdʒuəs/ · 3 syllables

Meaning

adjective

1. characterized by effort to the point of exhaustion; especially physical effort
   “worked their arduous way up the mining valley”
2. taxing to the utmost; testing powers of endurance- F.D.Roosevelt
   “his final, straining burst of speed”
3. difficult to accomplish; demanding considerable mental effort and skill
   “the arduous work of preparing a dictionary”

Synonyms for arduous

• backbreaking
• grueling
• gruelling
• hard
• heavy
• laborious
• operose
• punishing
• toilsome
• effortful
• straining
• strenuous
• difficult