The Collaborative International Dictionary of English v.0.48:

Perquisite \Per"qui*site\, n. [L. perquisitum, fr. perquisitus,
   p. p. of perquirere to ask for diligently; per + quaerere to
   seek. See Per-, and Quest.]
   1. Something gained from a place or employment over and above
      the ordinary salary or fixed wages for services rendered;
      -- examples are, a fee allowed by law to an officer for a
      specific service; the use of a company automobile or other
      company property.

   Syn: perk.
        [1913 Webster + PJC]

              The pillage of a place taken by storm was regarded
              as the perquisite of the soldiers.  --Prescott.
        [1913 Webster]

              The best perquisites of a place are the advantages
              it gaves a man of doing good.       --Addison.
        [1913 Webster]

   2. pl. (Law) Things gotten by a man's own industry, or
      purchased with his own money, as opposed to things which
      come to him by descent. --Mozley & W.
      [1913 Webster]

WordNet (r) 3.0 (2006):

perquisite
    n 1: an incidental benefit awarded for certain types of
         employment (especially if it is regarded as a right); "a
         limousine is one of the fringe benefits of the job" [syn:
         fringe benefit, perquisite, perk]
    2: a right reserved exclusively by a particular person or group
       (especially a hereditary or official right); "suffrage was
       the prerogative of white adult males" [syn: prerogative,
       privilege, perquisite, exclusive right]