representative — a person or thing that represents another or others.
ambassador — An ambassador is an important official who lives in a foreign country and represents his or her own country's interests there.
messenger — a person who carries a message or goes on an errand for another, especially as a matter of duty or business.
agent — A chemical that has a particular effect or is used for a particular purpose can be referred to as a particular kind of agent.
delegate — A delegate is a person who is chosen to vote or make decisions on behalf of a group of other people, especially at a conference or a meeting.
deputy — A deputy is the second most important person in an organization such as a business or government department. Someone's deputy often acts on their behalf when they are not there.
go-between — a person who acts as an agent or intermediary between persons or groups; emissary.
intermediary — an intermediate agent or agency; a go-between or mediator.
bearer — The bearer of something such as a message is the person who brings it to you.
carrier — A carrier is a vehicle that is used for carrying people, especially soldiers, or things.
consul — A consul is an official who is sent by his or her government to live in a foreign city in order to look after all the people there that belong to his or her own country.
courier — A courier is a person who is paid to take letters and parcels direct from one place to another.
herald — (formerly) a royal or official messenger, especially one representing a monarch in an ambassadorial capacity during wartime.
internuncio — a papal ambassador ranking next below a nuncio.
legate — an ecclesiastic delegated by the pope as his representative.
rep — Nucleonics. a unit proposed as a supplement to roentgen for expressing dosage of ionizing radiation: subsequently abandoned.
scout — a soldier, warship, airplane, etc., employed in reconnoitering.
spy — a person employed by a government to obtain secret information or intelligence about another, usually hostile, country, especially with reference to military or naval affairs.
hired gun — a person hired to kill someone, as a gunfighter or professional killer.
