a·gent (??j?nt)n.1. One that acts or has the power or authority to act.2. One empowered to act for or represent another: an author’s agent; an insurance agent.3. A means by which something is done or caused; an instrument.4. A force or substance that causes a change: a chemical agent; an infectious agent.5. A representative or official of a government or administrative department of a government: an FBI agent.6. A spy.7. Linguistics The argument that expresses the means or cause of an action or event described by a phrase or clause. The noun John is the agent in the clause John threw the ball.v. a·gent·ed, a·gent·ing, a·gents v.tr. To act as an agent or representative for: Who will agent your next book?v.intr. To act as an agent or representative.[Middle English, from Latin ag?ns, agent-, present participle of agere, to do; see ag- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.agent (?e?d??nt) n1. a person who acts on behalf of another person, group, business, government, etc; representative2. a person or thing that acts or has the power to act3. a phenomenon, substance, or organism that exerts some force or effect: a chemical agent. 4. the means by which something occurs or is achieved; instrument: wind is an agent of plant pollination. 5. (Commerce) a person representing a business concern, esp a travelling salesman6. (Professions) Brit short for estate agent7. (Military) short for secret agent[C15: from Latin agent-, noun use of the present participle of agere to do] agential adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014a?gent (?e? d??nt) n. 1. a person or business authorized to act on another’s behalf. 2. a person or thing that acts or has the power to act. 3. a natural force or object producing or used for obtaining specific results: Many insects are agents of fertilization. 4. an active cause; an efficient cause. 5. a person who works for or manages an agency. 6. a person who acts in an official capacity for a government agency, as a law-enforcement officer or a spy: an FBI agent. 7. a linguistic form or construction, usu. 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. 8. a representative of a business firm, esp. a traveling salesperson. 9. a substance that causes a chemical reaction. Compare reagent. 10. a drug or chemical capable of eliciting a biological response. 11. an organism that is a cause or vector of disease. v.t. 12. to represent (a person or thing); act as an agent on: to agent a manuscript; Who agented that deal? [1570?80;