passably vs moderately

passably and moderately both are adverbs.

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

As adverbs, passably and moderately are synonyms defined as:

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

passably (adverb)	moderately (adverb)
to certain extent or degree	to certain extent or degree
	with moderation; in a moderate manner