/ Dictionary / Index T treason: Meaning and Definition of Find definitions for: trea•son Pronunciation: (trē'zun), [key] — n. the offense of acting to overthrow one's government or to harm or kill its sovereign. a violation of allegiance to one's sovereign or to one's state. the betrayal of a trust or confidence; breach of faith; treachery. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: treason (Thesaurus) treas. treasonable Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language