(in North America) of, denoting, or formed in the upper of two divisions of the Carboniferous period, which lasted 30 million years, during which coal measures were formed
See also Mississippian (sense 2)
noun
3.
an inhabitant or native of the state of Pennsylvania
4. the Pennsylvanian
Pennsylvanian in American English
(ˌpɛnsəlˈveɪnjən; ˌpɛnsəlˈveɪniən)
US
adjective
1.
of Pennsylvania
2. [sometimesp-]
designating or of the second and last geologic subdivision of the Carboniferous Period, characterized by the development of vast deposits of dead, coal-forming plant matter and the first conifers and reptiles