A dictionary definition seems appropriate:
a person or business authorized to act on another's behalf: Our agent in Hong Kong will ship the merchandise. A best-selling author needs a good agent.
a person or thing that acts or has the power to act.
a natural force or object producing or used for obtaining specific results: Many insects are agents of fertilization.
an active cause; an efficient cause.
a person who works for or manages an agency.
a person who acts in an official capacity for a government or private agency, as a guard, detective, or spy: an FBI agent; the secret agents of a foreign power.
a person responsible for a particular action: Who was the agent of this deed?
Grammar . a form or construction, usually a noun or noun phrase, denoting an animate being that performs or causes the action expressed by the verb, as the police in The car was found by the police.
Indian agent.
a representative of a business firm, especially a traveling salesperson; canvasser; solicitor.
Chemistry . a substance that causes a reaction.
Pharmacology . a drug or chemical capable of eliciting a biological response.
Pathology . any microorganism capable of causing disease.
British . a campaign manager; an election agent.
— adjective
acting; exerting power (opposed to patient).
— verb (used with object)
to represent (a person or thing) as an agent; act as an agent for: to agent a manuscript; Who agented that deal?
