/pluy"euh seen'/ , Geol.
adj.
1. noting or pertaining to an epoch of the Tertiary Period, occurring from 10 to 2 million years ago, and characterized by increased size and numbers of mammals, by the growth of mountains, and by global climatic cooling. See table under geologic time .
n.
2. the Pliocene Epoch or Series.
[ 1825-35; PLIO- + -CENE ]