Definition

1. Noun:
   • Fifth columnist / Insider agent: A person who is a member of an organization but secretly works to help an external party, often by providing information or assistance from within.
   • Inside man / Inside contact: A trusted person within a group who provides aid, access, or confidential information to someone on the outside.

Usage Examples

• Noun:
  • Nhờ có tay trong, họ đã biết được kế hoạch của đối thủ. (Thanks to an inside man, they learned their rival's plan.)
  • Bọn tội phạm có tay trong ở cảnh sát. (The criminals have a mole within the police.)
  • Muốn vào được khu vực đó phải có tay trong. (To enter that area, you need an inside contact.)

Advanced Usage

• The term often carries a negative connotation, implying secrecy, betrayal, or covert operations. It is commonly used in contexts of espionage, crime, competitive business, or any situation requiring confidential internal access.

Variants and Related Words

• Nội gián (n): Spy, infiltrator. A more formal term for a secret agent working within an organization.
• Người bên trong (n): Insider. A more neutral term for someone inside a group.

Synonyms

• Mole: A spy who works within an organization.
• Informant: A person who provides privileged information.
• Accomplice from within: A helper who is part of the targeted group.

Related Idioms

• Có tay trong: To have an inside contact.
  • Công ty đó thắng thầu vì họ có tay trong. (That company won the bid because they had an inside contact.)

noun

1. fifth columnist, assistant from within