- (n.) A symbol expressing forty units; as, 40 or xl.
- (n.) The sum of four tens; forty units or objects.
- (a.) Four times ten; thirty-nine and one more.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). forty. Retrieved September 24, 2026, from http://smartdefine.org/forty/definitions/2009766 |
| Chicago | Webster's. 2011. "forty" http://smartdefine.org/forty/definitions/2009766 (accessed September 24, 2026). |
| Harvard | Webster's 2011, forty, Smart Define, viewed 24 September, 2026, <http://smartdefine.org/forty/definitions/2009766>. |
| MLA | Webster's. "forty" 27 May 2011. Web. 24 September 2026. <http://smartdefine.org/forty/definitions/2009766> |