The Collaborative International Dictionary of English v.0.48:

deputy \dep"u*ty\ (d[e^]p"[-u]*t[y^]), n.; pl. Deputies
   (d[e^]p"[-u]*t[i^]z). [F. d['e]put['e], fr. LL. deputatus.
   See Depute.]
   1. One appointed as the substitute of another, and empowered
      to act for him, in his name or his behalf; a substitute in
      office; a lieutenant; a representative; a delegate; a
      vicegerent; as, the deputy of a prince, of a sheriff, of a
      township, etc.
      [1913 Webster]

            There was then [in the days of Jehoshaphat] no king
            in Edom; a deputy was king.           --1 Kings
                                                  xxii. 47.
      [1913 Webster]

            God's substitute,
            His deputy anointed in His sight.     --Shak.
      [1913 Webster]

   Note: Deputy is used in combination with the names of various
         executive officers, to denote an assistant empowered to
         act in their name; as, deputy collector, deputy
         marshal, deputy sheriff.
         [1913 Webster]

   2. A member of the Chamber of Deputies. [France]
      [1913 Webster]

   Chamber of Deputies, one of the two branches of the French
      legislative assembly; -- formerly called Corps
      L['e]gislatif. Its members, called deputies, are elected
      by the people voting in districts.

   Syn: Substitute; representative; legate; delegate; envoy;
        agent; factor.
        [1913 Webster]

WordNet (r) 3.0 (2006):

deputy
    n 1: someone authorized to exercise the powers of sheriff in
         emergencies [syn: deputy, deputy sheriff]
    2: an assistant with power to act when his superior is absent
       [syn: deputy, lieutenant]
    3: a member of the lower chamber of a legislative assembly (such
       as in France)
    4: a person appointed to represent or act on behalf of others
       [syn: deputy, surrogate]

The Devil's Dictionary (1881-1906):

DEPUTY, n.  A male relative of an office-holder, or of his bondsman.
The deputy is commonly a beautiful young man, with a red necktie and
an intricate system of cobwebs extending from his nose to his desk.
When accidentally struck by the janitor's broom, he gives off a cloud
of dust.

    "Chief Deputy," the Master cried,
    "To-day the books are to be tried
    By experts and accountants who
    Have been commissioned to go through
    Our office here, to see if we
    Have stolen injudiciously.
    Please have the proper entries made,
    The proper balances displayed,
    Conforming to the whole amount
    Of cash on hand -- which they will count.
    I've long admired your punctual way --
    Here at the break and close of day,
    Confronting in your chair the crowd
    Of business men, whose voices loud
    And gestures violent you quell
    By some mysterious, calm spell --
    Some magic lurking in your look
    That brings the noisiest to book
    And spreads a holy and profound
    Tranquillity o'er all around.
    So orderly all's done that they
    Who came to draw remain to pay.
    But now the time demands, at last,
    That you employ your genius vast
    In energies more active.  Rise
    And shake the lightnings from your eyes;
    Inspire your underlings, and fling
    Your spirit into everything!"
    The Master's hand here dealt a whack
    Upon the Deputy's bent back,
    When straightway to the floor there fell
    A shrunken globe, a rattling shell
    A blackened, withered, eyeless head!
    The man had been a twelvemonth dead.
                                                       Jamrach Holobom