The Collaborative International Dictionary of English v.0.48:

Deputation \Dep`u*ta"tion\, n. [Cf. F. d['e]putation. See
   Depute.]
   1. The act of deputing, or of appointing or commissioning a
      deputy or representative; office of a deputy or delegate;
      vicegerency.
      [1913 Webster]

            The authority of conscience stands founded upon its
            vicegerency and deputation under God. --South.
      [1913 Webster]

   2. The person or persons deputed or commissioned by another
      person, party, or public body to act in his or its behalf;
      delegation; as, the general sent a deputation to the enemy
      to propose a truce.
      [1913 Webster]

   By deputation, or In deputation, by delegated authority;
      as substitute; through the medium of a deputy. [Obs.]
      [1913 Webster]

            Say to great C[ae]sar this: In deputation
            I kiss his conquering hand.           --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

deputation
    n 1: a group of representatives or delegates [syn: deputation,
         commission, delegation, delegacy, mission]
    2: authorizing subordinates to make certain decisions [syn:
       delegating, delegation, relegating, relegation,
       deputation]

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "deputation":
   accession, agency, agentship, anointing, anointment, appointment,
   arrogation, assignment, assumption, authority, authorization,
   brevet, care, change, charge, commission, commissioning,
   commitment, committee, commutation, consecration, consignment,
   coronation, cure, delegated authority, delegation, deputyship,
   devolution, devolvement, displacement, election, embassy,
   empowerment, entrusting, entrustment, errand, exchange,
   executorship, exequatur, factorship, full power, jurisdiction,
   legation, legitimate succession, license, lieutenancy, mandate,
   mission, office, plenipotentiary power, power of attorney,
   power to act, procuration, proxy, purview, quid pro quo, regency,
   regentship, replacement, representation, responsibility, seizure,
   subcommittee, subrogation, substitution, succession, supersedence,
   superseding, supersedure, supersession, supplantation, supplanting,
   supplantment, switch, taking over, task, tit for tat, trust,
   trusteeship, usurpation, vicarious authority, vicariousness,
   warrant