1. without the knowledge of someone; unknown to
Usage: usually followed by ‘to’

Examples

• Unbeknown to her parents, she had been saving money for months.
• The company was making changes unbeknown to its employees.
• Unbeknown to the guests, the surprise party had been planned for weeks.
• He left the house unbeknown to his roommates.
• The problem had been growing unbeknown to management.
• Unbeknown to the students, the test had been postponed.