To isolate a person or organization means to cause them to lose their friends or supporters.

If you isolate yourself, or if something isolates you, you become physically or socially separated from other people.

If you isolate something such as an idea or a problem, you separate it from others that it is connected with, so that you can concentrate on it or consider it on its own.

To isolate a substance means to obtain it by separating it from other substances using scientific processes.

To isolate a sick person or animal means to keep them apart from other people or animals, so that their illness does not spread.