The Collaborative International Dictionary of English v.0.48:

Wicket \Wick"et\, n. [OE. wiket, OF. wiket, guichet, F. quichet;
   probably of Scand. origin; cf. Icel. v?k a small creek,
   inlet, bay, vik a corner.]
   [1913 Webster]
   1. A small gate or door, especially one forming part of, or
      placed near, a larger door or gate; a narrow opening or
      entrance cut in or beside a door or gate, or the door
      which is used to close such entrance or aperture. Piers
      Plowman. "Heaven's wicket." --Milton.
      [1913 Webster]

            And so went to the high street, . . . and came to
            the great tower, but the gate and wicket was fast
            closed.                               --Ld. Berners.
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            The wicket, often opened, knew the key. --Dryden.
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   2. A small gate by which the chamber of canal locks is
      emptied, or by which the amount of water passing to a
      water wheel is regulated.
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   3. (Cricket)
      (a) A small framework at which the ball is bowled. It
          consists of three rods, or stumps, set vertically in
          the ground, with one or two short rods, called bails,
          lying horizontally across the top.
      (b) The ground on which the wickets are set.
          [1913 Webster]

   4. A place of shelter made of the boughs of trees, -- used by
      lumbermen, etc. [Local, U. S.] --Bartlett.
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   5. (Mining) The space between the pillars, in postand-stall
      working. --Raymond.
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   Wicket door, Wicket gate, a small door or gate; a wicket.
      See def. 1, above. --Bunyan.

   Wicket keeper (Cricket), the player who stands behind the
      wicket to catch the balls and endeavor to put the batsman
      out.
      [1913 Webster]

WordNet (r) 3.0 (2006):

wicket door
    n 1: small gate or door (especially one that is part of a larger
         door) [syn: wicket, wicket door, wicket gate]