The Collaborative International Dictionary of English v.0.48:

Closet \Clos"et\, n. [OF. closet little inclosure, dim. of clos.
   See Close an inclosure.]
   1. A small room or apartment for retirement; a room for
      privacy.
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            A chair-lumbered closet, just twelve feet by nine.
                                                  --Goldsmith.
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            When thou prayest, enter into thy closet. --Matt.
                                                  vi. 6.
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   2. A small apartment, or recess in the side of a room, for
      household utensils, clothing, etc. --Dryden.
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   Closet sin, sin commited in privacy. --Bp. Hall.
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The Collaborative International Dictionary of English v.0.48:

Closet \Clos"et\, v. t. [imp. & p. p.Closeted p. pr. & vb. n.
   Closeting.]
   1. To shut up in, or as in, a closet; to conceal. [R.]
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            Bedlam's closeted and handcuffed charge. --Cowper.
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   2. To make into a closet for a secret interview.
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            He was to call a new legislature, to closet its
            members.                              --Bancroft.
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            He had been closeted with De Quadra.  --Froude.
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WordNet (r) 3.0 (2006):

closet
    n 1: a small room (or recess) or cabinet used for storage space
         [syn: cupboard, closet]
    2: a toilet in Britain [syn: water closet, closet, W.C.,
       loo]
    3: a tall piece of furniture that provides storage space for
       clothes; has a door and rails or hooks for hanging clothes
       [syn: wardrobe, closet, press]
    4: a small private room for study or prayer
    v 1: confine to a small space, as for intensive work