Breadcrumb Home > Dictionary > Index A abacus: Meaning and Definition of Find definitions for: ab•a•cus Pronunciation: (ab'u-kus, u-bak'us), [key] — pl. ab•a•cus•es, ab•a•ci a device for making arithmetic calculations, consisting of a frame set with rods on which balls or beads are moved. a slab forming the top of the capital of a column. See diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: abacus (Thesaurus) abaculus Abadan TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: recidivism Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language