captaincy vs office

captaincy and office both are nouns.

Word	Noun	Adjective	Verb	Adverb
captaincy	Yes	No	No	No
office	Yes	No	No	No

As nouns, office is a hypernym of captaincy; that is, office is a word with a broader meaning than captaincy:

Other hypernyms of captaincy include berth, place, position, post, situation.

captaincy (noun)	office (noun)
the post of captain	a religious rite or service prescribed by ecclesiastical authorities
	the actions and activities assigned to or required or expected of a person or group
	a job in an organization
	place of business where professional or clerical duties are performed
	professional or clerical workers in an office
	an administrative unit of government
	(of a government or government official) holding an office means being in power