Be-lēm'nite, n.

n. [Fr. bélemnite, Gr. βελεμνίτης, a fossil shell pointed like a dart, from βέλεμνον, dart, from βέλος, dart, from βάλλειν, to throw.] (Paleon.) A cylindrical, calcareous fossil, about as large as the finger, tapering to a point at the lower extremity, and hollow, with a conical cavity at the other end; the thunderstone. It is the internal bone of an animal related to the sepia, and belonging to an extinct family of cephalopods. The specimens are found in rocks of the Jurassic and Cretaceous ages. Dana.