The Collaborative International Dictionary
Treasonable \Trea"son*a*ble\, a. 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.
Syn: Treacherous; traitorous; perfidious; insidious.
[1913 Webster]
-- Trea"son*a*ble*ness, n. --
Trea"son*a*bly, adv.
Wiktionary
adv. In a treasonable manner.
WordNet
adv. in a disloyal and faithless manner; "he behaved treacherously"; "his wife played him false" [syn: faithlessly, traitorously, treacherously, false]
Usage examples of "treasonably".
Some think that he went to get proofs against the Parliamentary leaders in England of their having treasonably invited the Scottish people to come and help them.
When we were all out in the raw air and were steadily moving towards our business, I treasonably whispered to Joe, “I hope, Joe, we shan’t find them.
In one direction, people were heard noisily speculating whether the Goths would be driven from the walls by the soldiers of Rome, or be honoured by an invitation to conclude a peace with the august Empire, which they had so treasonably ventured to invade.