Merriam-Webster Collegiate Dictionary - aristocracy

 noun  (plural -cies)  Etymology: Middle French & Late Latin; Middle French aristocratie, from Late Latin aristocratia, from Greek aristokratia, from aristos best + -kratia -cracy  Date: 1561  1. government by the best individuals or by a small privileged class  2.  a. a government in which power is vested in a minority consisting of those believed to be best qualified  b. a state with such a government  3. a governing body or upper class usually made up of a hereditary nobility  4. the aggregate of those believed to be superior