Treasonable

a.

1.

Pertaining to treason; consisting of treason; involving the crime of treason, or partaking of its guilt. Most men's heads had been intoxicated with imaginations of plots and treasonable practices. - Clarendon.

Adj.

1.

treasonable - constituting treason; "a traitorous act"; "treasonable acts like sabotage" Synonyms: treasonous, traitorous

Judas-like, Trojan-horse, apostate, betraying, breakaway, collaborative, degenerate, disloyal, double-crossing, extreme, extremistic, factious, faithless, fifth-column, insurgent, insurrectionary, mutineering, mutinous, quisling, quislingistic, rebel, rebellious, recreant, renegade, revolutional, revolutionary, riotous, seditionary, seditious, subversive, tergiversant, tergiversating, traitorous, treasonous, turbulent, turncoat, two-timing