adjective. Relating to, constituting, or involving treason.

Of or pertaining to treason; consisting of treason; involving the crime of treason, or partaking of its guilt.

Synonyms See perfidious.

adjective. Pertaining to treason; consisting of treason; involving the crime of treason, or partaking of its guilt.

adjective. involving, or constituting treason

adjective. having the character of, or characteristic of, a traitor

"Lord Allen may have been wrong in his head, or ill-advised, or foolishly over-zealous, but his ill-tempered upbraiding of the Dublin Corporation for what he called their treasonable extravagance in thus honouring Swift, whom he deemed an enemy of the King, was the act of a fool."

constant  

disloyal  

atrocious  basest  blasphemous  diabolical  dishonourable  

Judas-like  Trojan-horse  apostate  betraying  breakaway