extension agent vs county agent

extension agent and county agent both are nouns.

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

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

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

Other synonyms of extension agent include agricultural agent.

extension agent (noun)	county 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