treacherously vs treasonably

treacherously and treasonably both are adverbs.

Word	Noun	Adjective	Verb	Adverb
treacherously	No	No	No	Yes
treasonably	No	No	No	Yes

As adverbs, treacherously and treasonably are synonyms defined as:

Other synonyms of treacherously include faithlessly, false, traitorously.

treacherously (adverb)	treasonably (adverb)
in a disloyal and faithless manner	in a disloyal and faithless manner