- The definition of an isolationist is a person who believes in keeping to one's own affairs rather than becoming involved in the affairs of others.
A person who believes that the United States should mind its own business and not interfere with things going on in other countries is an example of an isolationist.
isolationist definition by Webster's New World
a person who believes in or advocates isolation; specif., one who opposes the involvement of his or her own country in international alliances, agreements, etc.
of isolationists or their policy
- isolationism noun