intelligence service vs intelligence agency

intelligence service and intelligence agency both are nouns.

Word	Noun	Adjective	Verb	Adverb
intelligence service	Yes	No	No	No
intelligence agency	Yes	No	No	No

As nouns, intelligence service and intelligence agency are synonyms defined as:

intelligence service and intelligence agency: a unit responsible for gathering and interpreting information about an enemy

Other synonyms of intelligence service include intelligence.

intelligence service (noun)	intelligence agency (noun)
a unit responsible for gathering and interpreting information about an enemy	a unit responsible for gathering and interpreting information about an enemy