a. [ From Oriskany, in New York. ] (Geol.) Designating, or pertaining to, certain beds, chiefly limestone, characteristic of the latest period of the Silurian age. [ 1913 Webster ]

Oriskany period, a subdivision of the American Paleozoic system intermediate or transitional in character between the Silurian and Devonian ages. See Chart of Geology. [ 1913 Webster ]