passably vs reasonably

passably and reasonably both are adverbs.

Word	Noun	Adjective	Verb	Adverb
passably	No	No	No	Yes
reasonably	No	No	No	Yes

As adverbs, passably and reasonably are synonyms defined as:

Other synonyms of passably include fairly, jolly, middling, moderately, pretty, somewhat.

passably (adverb)	reasonably (adverb)
to certain extent or degree	to certain extent or degree
	with good sense or in a reasonable or intelligent manner