[a. F. volcanisme: see VOLCANO sb. and -ISM, and cf. VULCANISM.] The state, condition or character of being volcanic; volcanic action or phenomena.
1869. J. Phillips, Vesuv., v. 150. Even if no other indication of former volcanism be traceable.
1882. Geikie, Geol. Sk., 276. The vast number of fissures … appeared hardly to connect themselves with any known phase of volcanism.
1895. Pop. Sci. Monthly, March, 577. Much more attention than formerly is now paid to the study of volcanism.
