Breadcrumb Home > Dictionary > Index P pacer: Meaning and Definition of Find definitions for: pac•er Pronunciation: (pā'sur), [key] — n. a person or thing that paces. a standard-bred horse that is used for pacing in harness racing. a pacemaker. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pacer (Thesaurus) pacemaker pacesetter ✖ Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language