/ Dictionary / Index S syntonous: Meaning and Definition of Find definitions for: syn•to•nous Pronunciation: (sin'tn-us), [key] — adj. syntonic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. syntonize syntony Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language