/'plaɪstəsi:n; `plaɪstə,sin/
adj (geology 地质) of the epoch in the earth's history that started about a million years ago and lasted for about
800000 years, when glaciers covered most of the northern hemisphere 更新世的.

adj
[Date: 1800-1900; Language: Greek;Origin: pleistos 'most' + kainos 'recent']
belonging to the period in the Earth's history that started about two million years ago and ended about 10,000 years ago, when much of the Earth was covered with ice