E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
means that which bounds in or holds in hand. The starting-point of a sequence of events harnessed together like a team of horses; also the whole period of time from one epoch to another. Our present epoch is the Birth of Christ; previous to this epoch it was the Creation of the World. In this latter sense the word is synonymous with era. (Greek, epi-ccho.)
The incarnation of Christ is the greatest moral epoch in the universe of God.Stevens: Parables Unfolded (The Lost Sheep, p. 104).