probably vs believably

probably and believably both are adverbs.

Word	Noun	Adjective	Verb	Adverb
probably	No	No	No	Yes
believably	No	No	No	Yes

As adverbs, probably and believably are synonyms defined as:

probably and believably: easy to believe on the basis of available evidence

Other synonyms of probably include credibly, plausibly.

probably (adverb)	believably (adverb)
with considerable certainty; without much doubt	in a believable manner
easy to believe on the basis of available evidence	easy to believe on the basis of available evidence