/ Dictionary / Index T theoretical arithmetic: Meaning and Definition of Find definitions for: theoret'ical arith'metic Pronunciation: [key] arithmetic (def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. theoretical theoretician Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language