abaft vs astern

abaft and astern both are adverbs.

Word	Noun	Adjective	Verb	Adverb
abaft	No	No	No	Yes
astern	No	No	No	Yes

As adverbs, abaft and astern are synonyms defined as:

abaft and astern: at or near or toward the stern of a ship or tail of an airplane

Other synonyms of abaft include aft.

abaft (adverb)	astern (adverb)
at or near or toward the stern of a ship or tail of an airplane	(of a ship or an airplane) behind
	at or near or toward the stern of a ship or tail of an airplane
	stern foremost or backward