The Collaborative International Dictionary of English v.0.48:

Procuration \Proc`u*ra"tion\, n. [L. procuratio: cf. F.
   procuration. See Procure.]
   [1913 Webster]
   1. The act of procuring; procurement.
      [1913 Webster]

   2. The management of another's affairs.
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   3. The instrument by which a person is empowered to transact
      the affairs of another; a proxy.
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   4. (Ch. of Eng.) A sum of money paid formerly to the bishop
      or archdeacon, now to the ecclesiastical commissioners, by
      an incumbent, as a commutation for entertainment at the
      time of visitation; -- called also proxy.
      [1913 Webster]

   Procuration money (Law), money paid for procuring a loan.
      --Blackstone.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

PROCURATION, civil law. The act by which one person gives power to another
to act in his place, as he could do himself. A letter of attorney.
    2. Procurations are either express or implied; an express procuration is
one made by the express consent of the parties; the implied or tacit takes
place when an individual sees another managing his affairs, and does not
interfere to prevent it. Dig. 17, 1, 6, 2; Id. 50, 17, 60; Code 7, 32, 2.
     3. Procurations are also divided into those which contain absolute
power, or a general authority, and those which give only a limited power.
Dig. 3, 3, 58; Id. 17, 1, 60, 4 4. The procurations are ended in three ways
first, by the revocation of the authority; secondly, by the death of one of
the parties; thirdly, by the renunciation of the mandatory, when it is made
in proper time and place, and it can be done without injury to the person
who gave it. Inst. 3, 27 Dig. 17, 1; Code 4, 35; and see Authority; Letter
of Attorney; Mandate.