possibly vs perhaps

possibly and perhaps both are adverbs.

Word	Noun	Adjective	Verb	Adverb
possibly	No	No	No	Yes
perhaps	No	No	No	Yes

As adverbs, possibly and perhaps are synonyms defined as:

Other synonyms of possibly include maybe, mayhap, peradventure, perchance.

possibly (adverb)	perhaps (adverb)
by chance	by chance
to a degree possible of achievement or by possible means