county agent vs extension agent

county agent and extension agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
county agent	Yes	No	No	No
extension agent	Yes	No	No	No

As nouns, county agent and extension agent are synonyms defined as:

county agent and extension agent: an advisor employed by the government to assist people in rural areas with methods of farming and home economics

Other synonyms of county agent include agricultural agent.

county agent (noun)	extension agent (noun)
an advisor employed by the government to assist people in rural areas with methods of farming and home economics	an advisor employed by the government to assist people in rural areas with methods of farming and home economics