'Treasonable' definitions:

Definition of 'treasonable'

From: WordNet
adjective
Having the character of, or characteristic of, a traitor; "the faithless Benedict Arnold"; "a lying traitorous insurrectionist" [syn: faithless, traitorous, unfaithful, treasonable, treasonous]

Definition of 'Treasonable'

From: GCIDE
  • Treasonable \Trea"son*a*ble\, a. Pertaining to treason; consisting of treason; involving the crime of treason, or partaking of its guilt. [1913 Webster]
  • Most men's heads had been intoxicated with imaginations of plots and treasonable practices. --Clarendon. [1913 Webster]
  • Syn: Treacherous; traitorous; perfidious; insidious. [1913 Webster] --{Trea"son*a*ble*ness}, n. -- {Trea"son*a*bly}, adv. [1913 Webster]

Synonyms of 'treasonable'

From: Moby Thesaurus