(n.) A letter of the Greek alphabet corresponding to th in English; -- sometimes called the unlucky letter, from being used by the judges on their ballots in passing condemnation on a prisoner, it being the first letter of the Greek qa`natos, death.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). theta. Retrieved September 21, 2026, from http://smartdefine.org/theta/definitions/2072045 |
| Chicago | Webster's. 2011. "theta" http://smartdefine.org/theta/definitions/2072045 (accessed September 21, 2026). |
| Harvard | Webster's 2011, theta, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/theta/definitions/2072045>. |
| MLA | Webster's. "theta" 28 May 2011. Web. 21 September 2026. <http://smartdefine.org/theta/definitions/2072045> |