pleistocene

/P L AY1 S T AH0 S IY0 N/
noun
  1. 1

    (geology) The Pleistocene epoch.

adjective
  1. 1

    (geology) Of a geologic epoch within the Quaternary period from about 2,588,000 to 11,700 years ago (earlier definition 1.7 million to 11,000 years ago); marked by the evolution of man, and the extinction of the large mammals.