skulduggery vs deceit

skulduggery and deceit both are nouns.

Word	Noun	Adjective	Verb	Adverb
skulduggery	Yes	No	No	No
deceit	Yes	No	No	No

As nouns, deceit is a hypernym of skulduggery; that is, deceit is a word with a broader meaning than skulduggery:

skulduggery: verbal misrepresentation intended to take advantage of you in some way
deceit: a misleading falsehood

Other hypernyms of skulduggery include deception, misrepresentation.

skulduggery (noun)	deceit (noun)
verbal misrepresentation intended to take advantage of you in some way	the act of deceiving
	the quality of being fraudulent
	a misleading falsehood