/ Dictionary / Index T tourmaline: Meaning and Definition of Find definitions for: tour•ma•line Pronunciation: (toor'mu-lin, -lēn"), [key] — n. any of a group of silicate minerals of complex composition, containing boron, aluminum, etc., usually black but having various colored, transparent varieties used as gems. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tourmaline (Thesaurus) tour jeté Tournai Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language