/ Dictionary / Index A arith.: Meaning and Definition of Find definitions for: arith. Pronunciation: [key] arithmetic. arithmetical. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. aristotype arithmancy Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language