1. to cause someone to feel isolated, unwelcome, or disconnected from a group, community, or relationship
Usage: transitive verb; often used in the form 'estrange' (more common); 'estranger' is the agent noun

Examples

• His harsh words made him an estranger of his own family.
• The estranger's actions drove a wedge between longtime friends.
• She became an estranger to the community after the scandal.
• The estranger's influence poisoned relationships within the group.