epoch Definition

epoch
noun

1. A major division or period of history, or of a person's life, etc, usually marked by some important event.

Thesaurus: era, time, period, age, date.
2. geol.
An interval of geological time representing a subdivision of a period, and during which a particular series of rocks was formed.

Derivative: epochal
adj

Relating to, or lasting for, an epoch.

Etymology: 17c: from Greek epoche fixed point.