Answer: Proxy. Explanation: Sometimes it helps to have someone else who can speak on your behalf and represent your interests, especially in formal situations or when you don't feel very confident. A person who speaks on your behalf in this way is often called an 'advocate'. you do something on someone's behalf, that means that you do something for them. ex: I will be listening to your case on the behalf of my client. if you do something on someone's behalf, that means that you do something for them. ex: I will be listening to your case on the behalf of my client. In behalf of” means “for the benefit of” or “in the interest of.” “On behalf of” means “in place of” or “as the agent of.” So I might give a donation, “on behalf of” my gardening club, to be used “in behalf of” tree restoration in the park.