Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun pennsylvanian_period

1 sense of pennsylvanian period

Sense 1
Pennsylvanian, Pennsylvanian period, Upper Carboniferous, Upper Carboniferous period -- (from 310 million to 280 million years ago; warm climate; swampy land)
       INSTANCE OF=> period, geological period -- (a unit of geological time during which a system of rocks formed; "ganoid fishes swarmed during the earlier geological periods")