- (a.) Steep and lofty, in a literal sense; hard to climb.
- (a.) Attended with great labor, like the ascending of acclivities; difficult; laborious; as, an arduous employment, task or enterprise.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). arduous. Retrieved September 20, 2026, from http://smartdefine.org/arduous/definitions/1975654 |
| Chicago | Webster's. 2011. "arduous" http://smartdefine.org/arduous/definitions/1975654 (accessed September 20, 2026). |
| Harvard | Webster's 2011, arduous, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/arduous/definitions/1975654>. |
| MLA | Webster's. "arduous" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/arduous/definitions/1975654> |