/ Dictionary / Index S Syncom: Meaning and Definition of Find definitions for: Syn•com Pronunciation: (sin'kom), [key] — n. U.S. Aerospace. one of a series of experimental communications satellites that were the first to be placed in geostationary orbit. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. synclinorium syncopate 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