(a.) Happening every eighth year; also, lasting a period of eight years.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). octennial. Retrieved September 20, 2026, from http://smartdefine.org/octennial/definitions/2038289 |
| Chicago | Webster's. 2011. "octennial" http://smartdefine.org/octennial/definitions/2038289 (accessed September 20, 2026). |
| Harvard | Webster's 2011, octennial, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/octennial/definitions/2038289>. |
| MLA | Webster's. "octennial" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/octennial/definitions/2038289> |