1. to be disloyal to someone who trusts you
2. to reveal or show something that was meant to be hidden
3. to give secret information about someone to an enemy

Examples

• She felt hurt when her best friend betrays her trust.
• His nervous laugh betrays his anxiety about the test.
• The spy betrays his country by selling military secrets.
• Her face betrays no emotion during the difficult conversation.
• He betrays his teammates by sharing their strategy with opponents.
• The crack in the wall betrays the building’s structural problems.
• She never betrays a confidence when friends tell her secrets.