- (n.) A division of time characterized by the prevalence of similar conditions of the earth; commonly a minor division or part of a period.
- (n.) An arbitrary fixed date, for which the elements used in computing the place of a planet or other heavenly body, at any other date, are given; as, the epoch of Mars; lunar elements for the epoch March 1st, 1860.
- (n.) A period of time, longer or shorter, remarkable for events of great subsequent influence; a memorable period; as, the epoch of maritime discovery or of the Reformation.
- (n.) A fixed point of time, established in history by the occurrence of some grand or remarkable event; a point of time marked by an event of great subsequent influence; as, the epoch of the creation; the birth of Christ was the epoch which gave rise to the Christian era.
- (n.) The date at which a planet or comet has a longitude or position.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). epoch. Retrieved September 21, 2026, from http://smartdefine.org/epoch/definitions/2004327 |
| Chicago | Webster's. 2011. "epoch" http://smartdefine.org/epoch/definitions/2004327 (accessed September 21, 2026). |
| Harvard | Webster's 2011, epoch, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/epoch/definitions/2004327>. |
| MLA | Webster's. "epoch" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/epoch/definitions/2004327> |