- (n.) The Ordovician formation.
- (a.) Of or pertaining to a division of the Silurian formation, corresponding in general to the Lower Silurian of most authors, exclusive of the Cambrian.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). ordovician. Retrieved September 29, 2026, from http://smartdefine.org/ordovician/definitions/2039338 |
| Chicago | Webster's. 2011. "ordovician" http://smartdefine.org/ordovician/definitions/2039338 (accessed September 29, 2026). |
| Harvard | Webster's 2011, ordovician, Smart Define, viewed 29 September, 2026, <http://smartdefine.org/ordovician/definitions/2039338>. |
| MLA | Webster's. "ordovician" 27 May 2011. Web. 29 September 2026. <http://smartdefine.org/ordovician/definitions/2039338> |