scepticism vs disbelief

scepticism and disbelief both are nouns.

Word	Noun	Adjective	Verb	Adverb
scepticism	Yes	No	No	No
disbelief	Yes	No	No	No

As nouns, disbelief is a hypernym of scepticism; that is, disbelief is a word with a broader meaning than scepticism:

Other hypernyms of scepticism include unbelief.

As nouns, scepticism and disbelief are synonyms defined as:

Other synonyms of scepticism include incredulity, mental rejection, skepticism.

scepticism (noun)	disbelief (noun)
the disbelief in any claims of ultimate knowledge	doubt about the truth of something
doubt about the truth of something	a rejection of belief