An epeiric sea, also known as an epicontinental sea, is a shallow sea that extends over a large part of a continent, typically during periods of high sea levels. These seas are significant in paleogeography and sedimentology, as they are often associated with extensive sedimentary deposits and fossil-rich layers.
Source Johnson, M. E., & Boucot, A. J. (1996). “Paleogeography and Paleobiogeography: Biodiversity in Shallow Seas.” Geological Society of America Special Paper 306.