skepticism vs doubt

skepticism and doubt both are nouns.

Word	Noun	Adjective	Verb	Adverb
skepticism	Yes	No	No	No
doubt	Yes	No	Yes	No

As nouns, doubt is a hypernym of skepticism; that is, doubt is a word with a broader meaning than skepticism:

Other hypernyms of skepticism include doubtfulness, dubiety, dubiousness, incertitude, uncertainty.

skepticism (noun)	doubt (noun)
doubt about the truth of something	uncertainty about the truth or factuality or existence of something
the disbelief in any claims of ultimate knowledge	the state of being unsure of something

skepticism (verb)	doubt (verb)
	consider unlikely
	lack confidence in