[tree-zuh 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.

Origin of treason

1175–1225; Middle English tre(i)so(u)n < Anglo-French; Old French traïson < Latin trāditiōn- (stem of trāditiō) a handing over, betrayal. See tradition
Related formssu·per·trea·son, noun

Synonym study

1. Treason , sedition mean disloyalty or treachery to one's country or its government. Treason is any attempt to overthrow the government or impair the well-being of a state to which one owes allegiance; the crime of giving aid or comfort to the enemies of one's government. Sedition is any act, writing, speech, etc., directed unlawfully against state authority, the government, or constitution, or calculated to bring it into contempt or to incite others to hostility, ill will or disaffection; it does not amount to treason and therefore is not a capital offense. 2. See disloyalty. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for treason

Contemporary Examples of treason

Historical Examples of treason

  • Go—leave me, minister of death, commencement of sin, and child of treason!

    The Dream

    Emile Zola

  • The thought staggered him, and he felt as if he had filled his mind with treason and sedition!

    The Foolish Lovers

    St. John G. Ervine

  • If his talk stinks not of treason in every line, why then I have no smelling sense.

    In the Valley

    Harold Frederic

  • The organs of treason and of infamy refer always to McClellan.

  • He thought she went to find a confidant outside, that she was preparing her treason.

    Therese Raquin

    Emile Zola

British Dictionary definitions for treason



violation or betrayal of the allegiance that a person owes his sovereign or his country, esp by attempting to overthrow the government; high treason
any treachery or betrayal
Derived Formstreasonable or treasonous, adjectivetreasonableness, nountreasonably, adverb

Word Origin for treason

C13: from Old French traïson, from Latin trāditiō a handing over; see tradition, traditor
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for treason

early 13c., from Anglo-French treson, from Old French traison (11c.; Modern French trahison), from Latin traditionem (nominative traditio) "a handing over, delivery, surrender" (see tradition). Old French form influenced by the verb trair "betray." In old English law, high treason is violation by a subject of his allegiance to his sovereign or to the state; distinguished from petit treason, treason against a subject, such as murder of a master by his servant.

Online Etymology Dictionary, © 2010 Douglas Harper