Downing Street vs government

Downing Street and government both are nouns.

Word	Noun	Adjective	Verb	Adverb
Downing Street	Yes	No	No	No
government	Yes	No	No	No

As nouns, government is a hypernym of Downing Street; that is, government is a word with a broader meaning than Downing Street:

Downing Street: the British government
government: the organization that is the governing authority of a political unit

Other hypernyms of Downing Street include authorities, regime.

Downing Street (noun)	government (noun)
the British government	the act of governing; exercising authority
a street of Westminster in London	(government) the system or form by which a community or other political unit is governed
	the study of government of states and other political units
	the organization that is the governing authority of a political unit