/ Dictionary / Index V volcanism: Meaning and Definition of Find definitions for: vol•can•ism Pronunciation: (vol'ku-niz"um), [key] — n. Geol. the phenomena connected with volcanoes and volcanic activity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: volcanism (Thesaurus) volcanic tuff volcano Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language