term:

Treason

treason n

[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]
: the offense of attempting to overthrow the government of one's country or of assisting its enemies in war
;specif
: 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
trea·son·ous [-əs]
adj

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.