Noun epoch has 3 senses
  1. era, epoch - a period marked by distinctive character or reckoned from a fixed point or event
    --1 is a kind of time period, period of time, period
    --1 has particulars:
     Caliphate; Christian era, Common era; day; historic period, age; modern era
  2. epoch, date of reference - (astronomy) the precise date that is the point of reference for which information (as coordinates of a celestial body) is referred
    --2 is a kind of date
  3. epoch - a unit of geological time
    --3 is a kind of
    geological time, geologic time
    --3 is a part of period, geological period
    --3 has particulars:
     Holocene, Holocene epoch, Recent epoch; Pleistocene, Pleistocene epoch, Glacial epoch; Pliocene, Pliocene epoch; Miocene, Miocene epoch; Oligocene, Oligocene epoch; Eocene, Eocene epoch; Paleocene, Paleocene epoch