1. friendly association or interaction between people or groups, especially those from different social classes, nations, or military forces
Usage: British spelling; American spelling is 'fraternization'; often used in historical or military contexts
2. friendly contact or cooperation between enemy soldiers during wartime
Usage: military/historical context

Examples

• The fraternisation between the two rival teams after the match showed good sportsmanship.
• During the war, fraternisation between soldiers from opposing sides was strictly forbidden.
• The company encouraged fraternisation among employees from different departments to build unity.
• Historical accounts describe fraternisation between occupying forces and local civilians.
• The policy aimed to prevent fraternisation between management and workers to maintain professional boundaries.
• Cultural fraternisation between the two nations helped ease diplomatic tensions.