agency vs fast track

agency and fast track both are nouns.

Word	Noun	Adjective	Verb	Adverb
agency	Yes	No	No	No
fast track	Yes	No	No	No

As nouns, fast track is a hyponym of agency; that is, fast track is a word with a more specific, narrower meaning than agency:

agency: to have the ability to produce a particular effect or achieve an end
fast track: a rapid means of achieving a goal

agency (noun)	fast track (noun)
to have the ability to produce a particular effect or achieve an end	a rapid means of achieving a goal
an administrative unit of government
a business or organization that provides a particular service, especially the mediation of transactions between two parties
the state of serving as an official and authorized delegate or agent
the state of being in action or exerting power