/ Dictionary / Index S syntonic: Meaning and Definition of Find definitions for: syn•ton•ic Pronunciation: (sin-ton'ik), [key] — adj. adjusted to oscillations of the same or a particular frequency. of or denoting a personality characterized by normal emotional responsiveness to the environment. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. synthpop syntonize Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language