Both sides agreed to bring in a third-party to mediate their business dispute.

third-party 是由 third（第三）和 party（一方、团体）组成的复合词，字面意思是"第三方"。 在商业或法律语境中，third-party 指与争议双方无关的独立个人或组织，通常作为中立方介入调解或仲裁。