treason

noun

trea·​son ˈtrē-zᵊn 

1

: the offense of attempting by overt acts to overthrow the government of the state to which the offender owes allegiance or to kill or personally injure the sovereign or the sovereign's family

2

: the betrayal of a trust : treachery

Synonyms

• backstabbing
• betrayal
• business
• disloyalty
• double cross
• faithlessness
• falseness
• falsity
• infidelity
• perfidy
• sellout
• treachery
• two-timing
• unfaithfulness

Examples of treason in a Sentence

He is guilty of treason.

reading a friend's diary without permission would have to be regarded as the ultimate act of personal treason

Recent Examples on the Web

Buying American now seems like an act of treason here. —Matthew J. Friedman, CNN Money, 1 Apr. 2025

Wolsey died in Season 1, but not before bequeathing his showcase to Henry, who returned the favor by accusing his chief minister of treason. —Bryan Alexander, USA Today, 30 Mar. 2025

In addition, pro-democracy groups fear that Musk’s army of 20-somethings examining USAID’s contracts may disclose the names of the organizations receiving U.S. funding, putting their staffs in danger of immediate arrest in countries where accepting USAID money would be treason. —Andres Oppenheimer, Miami Herald, 7 Feb. 2025

Henry’s five resolutions rejected the crown’s right to unilaterally tax the American Colonies; his speech defending the resolves was so fiery that some in the audience accused him of treason. —Cassandra Good, Smithsonian Magazine, 21 Mar. 2025

Word History

Etymology

Middle English tresoun, from Anglo-French traisun, from Latin tradition-, traditio act of handing over, from tradere to hand over, betray — more at traitor

First Known Use

13th century, in the meaning defined at sense 2

Phrases Containing treason

• high treason

Rhymes for treason

• reason
• season
• seizin
• milesian
• partizan
• postseason
• preseason
• unreason

Kids Definition

treason

noun

trea·​son ˈtrēz-ᵊn 

1

: the betrayal of a trust : treachery

2

: the crime of attempting to overthrow the government of one's country or of attempting to kill or injure the ruler or the ruler's family

Etymology

Middle English tresoun "treason," from early French traisun (same meaning), from Latin tradition-, traditio "the action of handing over, tradition, betrayal," from tradere "to hand over, betray," from tra-, trans- "across" and dare "to give" — related to tradition, traitor

Word Origin

The words treason and tradition both come from the same Latin source. The Latin word traditio meant "teaching" or "tradition." These senses developed from its basic meaning, which was "the act of handing something over." Tradition is maintained by passing information from one generation to another. One kind of treason is committed when someone who has been entrusted with secret information passes it on to someone else. The word tradition was borrowed directly from the Latin traditio. Treason, on the other hand, came to us through early French, where traditio had changed into the word traisun.

Legal Definition

treason

noun

trea·​son ˈtrēz-ᵊn 

: the offense of attempting to overthrow the government of one's country or of assisting its enemies in war

specifically : the act of levying war against the United States or adhering to or giving aid and comfort to its enemies by one who owes it allegiance

treasonous

-əs 

adjective

Etymology

Anglo-French treison crime of violence against a person to whom allegiance is owed, literally, betrayal, from Old French traïson, from traïr to betray, from Latin tradere to hand over, surrender