The Collaborative International Dictionary of English v.0.48:

Rummage \Rum"mage\ (?; 48), n. [For roomage, fr. room; hence
   originally, a making room, a packing away closely. See
   Room.]
   1. (Naut.) A place or room for the stowage of cargo in a
      ship; also, the act of stowing cargo; the pulling and
      moving about of packages incident to close stowage; --
      formerly written romage. [Obs.]
      [1913 Webster]

   2. A searching carefully by looking into every corner, and by
      turning things over.
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            He has made such a general rummage and reform in the
            office of matrimony.                  --Walpole.
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   Rummage sale, a clearance sale of unclaimed goods in a
      public store, or of odds and ends which have accumulated
      in a shop. --Simmonds.
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The Collaborative International Dictionary of English v.0.48:

Rummage \Rum"mage\, v. i.
   To search a place narrowly.
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         I have often rummaged for old books in Little Britain
         and Duck Lane.                           --Swift.
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         [His house] was haunted with a jolly ghost, that . . .
         . . . rummaged like a rat.               --Tennyson.
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The Collaborative International Dictionary of English v.0.48:

Rummage \Rum"mage\, v. t. [imp. & p. p. Rummaged; p. pr. & vb.
   n. Rummaging.]
   1. (Naut.) To make room in, as a ship, for the cargo; to move
      about, as packages, ballast, so as to permit close
      stowage; to stow closely; to pack; -- formerly written
      roomage, and romage. [Obs.]
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            They might bring away a great deal more than they
            do, if they would take pain in the romaging.
                                                  --Hakluyt.
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   2. To search or examine thoroughly by looking into every
      corner, and turning over or removing goods or other
      things; to examine, as a book, carefully, turning over
      leaf after leaf.
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            He . . . searcheth his pockets, and taketh his keys,
            and so rummageth all his closets and trunks.
                                                  --Howell.
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            What schoolboy of us has not rummaged his Greek
            dictionary in vain for a satisfactory account! --M.
                                                  Arnold.
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WordNet (r) 3.0 (2006):

rummage
    n 1: a jumble of things to be given away
    2: a thorough search for something (often causing disorder or
       confusion); "he gave the attic a good rummage but couldn't
       find his skis" [syn: ransacking, rummage]
    v 1: search haphazardly; "We rummaged through the drawers"