Downing Street vs street

Downing Street and street both are nouns.

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

Downing Street (noun)	street (noun)
the British government	a thoroughfare (usually including sidewalks) that is lined with buildings
a street of Westminster in London	the part of a thoroughfare between the sidewalks; the part of the thoroughfare on which vehicles travel
	people living or working on the same street
	the streets of a city viewed as a depressed environment in which there is poverty and crime and prostitution and dereliction
	a situation offering opportunities