代理人 (dài lǐ rén): ตัวแทน

He signed that contract as the company's agent.

This agent has the authority to negotiate on behalf of the client.

She hired a lawyer as her agent to handle the case.

Agents must abide by laws and ethical norms in transactions.

Our agent will represent us at next week's meeting.

He was appointed as a plenipotentiary agent, responsible for handling all related matters.