Of or belonging to the geologic time, system of rocks, or sedimentary deposits of the sixth period of the Paleozoic Era, characterized by the development of the amniotic egg, the appearance of the first reptiles, and widespread swamp forests. See Table at geologic time.
n.
A native or resident of Pennsylvania.
The Pennsylvanian Period. Also called Upper Carboniferous.
(pěn'səl-vān'yən, -vā'nē-ən) 