agent

noun Etymology: Middle English, from Medieval Latin agent-, agens, from Latin, present participle of agere to drive, lead, act, do; akin to Old Norse aka to travel in a vehicle, Greek agein to drive, lead Date: 15th century 1. one that acts or exerts power 2. a. something that produces or is capable of producing an effect ; an active or efficient cause b. a chemically, physically, or biologically active principle 3. a means or instrument by which a guiding intelligence achieves a result 4. one who is authorized to act for or in the place of another: as a. a representative, emissary, or official of a government <

crown agent

> <

federal agent

> b. one engaged in undercover activities (as espionage) ; spy <

secret agent

> c. a business representative (as of an athlete or entertainer) <

a theatrical agent

> 5. a computer application designed to automate certain tasks (as gathering information online)