n. [ OE. tresun, treisun, traisoun, OF. traïson, F. trahison, L. traditio a giving up, a delivering up, fr. tradere to give up, betray. See Traitor, and cf. Tradition. ] 1. The offense of attempting to overthrow the government of the state to which the offender owes allegiance, or of betraying the state into the hands of a foreign power; disloyalty; treachery. [ 1913 Webster ]

The treason of the murthering in the bed. Chaucer. [ 1913 Webster ]

☞ In monarchies, the killing of the sovereign, or an attempt to take his life, is treason. In England, to imagine or compass the death of the king, or of the queen consort, or of the heir apparent to the crown, is high treason, as are many other offenses created by statute. In the United States, treason is confined to the actual levying of war against the United States, or to an adhering to their enemies, giving them aid and comfort. [ 1913 Webster ]

2. Loosely, the betrayal of any trust or confidence; treachery; perfidy. [ 1913 Webster ]

If he be false, she shall his treason see. Chaucer. [ 1913 Webster ]

Petit treason. See under Petit. [ 1913 Webster ]

a. Pertaining to treason; consisting of treason; involving the crime of treason, or partaking of its guilt. [ 1913 Webster ]

Most men's heads had been intoxicated with imaginations of plots and treasonable practices. Clarendon. [ 1913 Webster ]

Syn. -- Treacherous; traitorous; perfidious; insidious. [ 1913 Webster ]

--Trea"son*a*ble*ness, n. -- Trea"son*a*bly, adv. [ 1913 Webster ]

a. Treasonable. Shak. [ 1913 Webster ]

The treasonous book of the Court of King James. Pepys. [ 1913 Webster ]