amazingly vs astonishingly

amazingly and astonishingly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
amazingly	No	No	No	Yes
astonishingly	No	No	No	Yes

As adverbs, amazingly and astonishingly are synonyms defined as:

amazingly and astonishingly: in an amazing manner; to everyone's surprise

Other synonyms of amazingly include surprisingly.

amazingly (adverb)	astonishingly (adverb)
in an amazing manner; to everyone's surprise	in an amazing manner; to everyone's surprise