- having the character of, or characteristic of, a traitor;
"the faithless Benedict Arnold"
"a lying traitorous insurrectionist"
- Such actions come near to treason.
- They have committed treason against the state.
- He swore treason against his friend.
- He was beheaded for high treason.
- She was arraigned for high treason.
- His treasonous brother stole upon him in his sleep.