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.
- A particular period of history, especially one considered remarkable or noteworthy.
- A notable event that marks the beginning of such a period. See Synonyms at period.
- A unit of geologic time that is a division of a period.
- Astronomy An instant in time that is arbitrarily selected as a point of reference.