/ Dictionary / Index T tachism: Meaning and Definition of Find definitions for: tach•ism Pronunciation: (tash'iz-um), [key] — n. See(def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tachiol tachistoscope Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language