astonishingly vs amazingly

astonishingly and amazingly both are adverbs.

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

As adverbs, astonishingly and amazingly are synonyms defined as:

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

Other synonyms of astonishingly include surprisingly.

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