Merriam-Webster Collegiate Dictionary - proxy

 noun  (plural proxies)  Etymology: Middle English proxi, procucie, contraction of procuracie, from Anglo-French, from Medieval Latin procuratia, alteration of Latin procuratio procuration  Date: 15th century  1. the agency, function, or office of a deputy who acts as a substitute for another  2.  a. authority or power to act for another  b. a document giving such authority; specifically a power of attorney authorizing a specified person to vote corporate stock  3. a person authorized to act for another ; procurator  • ~ adjective