- (n.) The sum of three tens or twenty and ten; thirty units or objects.
- (n.) A symbol expressing thirty, as 30 or XXX.
- (a.) Being three times ten; consisting of one more than twenty-nine; twenty and ten; as, the month of June consists of thirty days.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). thirty. Retrieved September 22, 2026, from http://smartdefine.org/thirty/definitions/2072165 |
| Chicago | Webster's. 2011. "thirty" http://smartdefine.org/thirty/definitions/2072165 (accessed September 22, 2026). |
| Harvard | Webster's 2011, thirty, Smart Define, viewed 22 September, 2026, <http://smartdefine.org/thirty/definitions/2072165>. |
| MLA | Webster's. "thirty" 28 May 2011. Web. 22 September 2026. <http://smartdefine.org/thirty/definitions/2072165> |