Customs Service vs authority

Customs Service and authority both are nouns.

Word	Noun	Adjective	Verb	Adverb
Customs Service	Yes	No	No	No
authority	Yes	No	No	No

As nouns, authority is a hypernym of Customs Service; that is, authority is a word with a broader meaning than Customs Service:

Customs Service: the agency of the Treasury Department that enforces import tariffs
authority: an administrative unit of government

Other hypernyms of Customs Service include agency, bureau, federal agency, government agency, office.

Customs Service (noun)	authority (noun)
the agency of the Treasury Department that enforces import tariffs	the power or right to give orders or make decisions
	official permission or approval
	freedom from doubt; belief in yourself and your abilities
	an authoritative written work
	an administrative unit of government
	an expert whose views are taken as definitive
	(usually plural) persons who exercise (administrative) control over others