officialdom vs governance

officialdom and governance both are nouns.

Word	Noun	Adjective	Verb	Adverb
officialdom	Yes	No	No	No
governance	Yes	No	No	No

As nouns, governance is a hypernym of officialdom; that is, governance is a word with a broader meaning than officialdom:

officialdom: people elected or appointed to administer a government
governance: the persons (or committees or departments etc.) who make up a body for the purpose of administering something

Other hypernyms of officialdom include administration, brass, establishment, governing body, organisation, organization.

officialdom (noun)	governance (noun)
people elected or appointed to administer a government	the act of governing; exercising authority
	the persons (or committees or departments etc.) who make up a body for the purpose of administering something