Breadcrumb Home > 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: quadrumanous Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language