/ Dictionary / Index T tertiary syphilis: Meaning and Definition of Find definitions for: ter'tiary syph'ilis Pronunciation: [key] — Pathol. Pathol. the third stage of syphilis, characterized by involvement of the internal organs, esp. the brain, spinal cord, heart, and liver. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tertiary color tertium quid Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language