Definitions of isolation:

• noun:   the act of isolating something; setting something apart from others
• noun:   a country's withdrawal from internal politics

  Example: "He opposed a policy of American isolation"

• noun:   a feeling of being disliked and alone
• noun:   (psychiatry) a defense mechanism in which memory of an unacceptable act or impulse is separated from the emotion originally associated with it
• noun:   a state of separation between persons or groups
• noun:   preference for seclusion or isolation