afterwards vs after

afterwards is not an adjective while after is an adjective.

Word	Noun	Adjective	Verb	Adverb
afterwards	No	No	No	Yes
after	No	Yes	No	Yes

As adverbs, afterwards and after are synonyms defined as:

afterwards and after: happening at a time subsequent to a reference time

Other synonyms of afterwards include afterward, later, later on, subsequently.

afterwards (adjective)	after (adjective)
	located farther aft

afterwards (adverb)	after (adverb)
happening at a time subsequent to a reference time	behind or in the rear
	happening at a time subsequent to a reference time