|1.||a point in time beginning a new or distinctive period: the invention of nuclear weapons marked an epoch in the history of warfare|
|2.||a long period of time marked by some predominant or typical characteristic; era|
|3.||astronomy a precise date to which information, such as coordinates, relating to a celestial body is referred|
|4.||geology a unit of geological time within a period during which a series of rocks is formed: the Pleistocene epoch|
|5.||physics the displacement of an oscillating or vibrating body at zero time|
|[C17: from New Latin epocha, from Greek epokhē cessation; related to ekhein to hold, have]|
|epoch (ěp'ək, ē'pŏk') Pronunciation Key
The shortest division of geologic time. An epoch is a subdivision of a period.