faithlessly vs treasonably

faithlessly and treasonably both are adverbs.

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

As adverbs, faithlessly and treasonably are synonyms defined as:

Other synonyms of faithlessly include false, traitorously, treacherously.

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