adj. 1. Of or relating to Pennsylvania. 2. Of, relating to, or being the period of geologic time from about 318 to 299 million years ago, the sixth period of the Paleozoic Era. The Pennsylvanian Period is characterized by the appearance of the first reptiles and widespread swamp forests. See Table at geologic time. n. 1. A native or resident of Pennsylvania. 2. The Pennsylvanian Period. Also called Upper Carboniferous. [After Pennsylvania.] |
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