unfeignedly vs sincerely

unfeignedly and sincerely both are adverbs.

Word	Noun	Adjective	Verb	Adverb
unfeignedly	No	No	No	Yes
sincerely	No	No	No	Yes

As adverbs, unfeignedly and sincerely are synonyms defined as:

Other synonyms of unfeignedly include truly.

unfeignedly (adverb)	sincerely (adverb)
with sincerity; without pretense	with sincerity; without pretense
	written formula for ending a letter