Paleozoic has 5 different meanings across 3 categories:
Noun · Adjective · Proper Noun
from 544 million to about 230 million years ago
of or relating to or denoting the Paleozoic era
Of a geologic era within the Phanerozoic eon that comprises the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods from about 542 to 250 million years ago, from the age of trilobites to that of reptiles.
Alternative form of Paleozoic
The Paleozoic era.