adjective: Alternative spelling of Paleozoic [(geology) 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.]
noun: Alternative spelling of Paleozoic [(geology) The Paleozoic era.]
