Source : Webster's Revised Unabridged Dictionary (1913)

Chemung period \Che*mung" pe"ri*od\, (Geol.)
   A subdivision in the upper part of the Devonian system in
   America, so named from the Chemung River, along which the
   rocks are well developed. It includes the Portage and Chemung
   groups or epochs. See the Diagram under {Geology}.