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.
      [1913 Webster]

            He has made such a general rummage and reform in the
            office of matrimony.                  --Walpole.
      [1913 Webster]

   Rummage sale, a clearance sale of unclaimed goods in a
      public store, or of odds and ends which have accumulated
      in a shop. --Simmonds.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rummage \Rum"mage\, v. i.
   To search a place narrowly.
   [1913 Webster]

         I have often rummaged for old books in Little Britain
         and Duck Lane.                           --Swift.
   [1913 Webster]

         [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.]
      [1913 Webster]

            They might bring away a great deal more than they
            do, if they would take pain in the romaging.
                                                  --Hakluyt.
      [1913 Webster]

   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.
      [1913 Webster]

            He . . . searcheth his pockets, and taketh his keys,
            and so rummageth all his closets and trunks.
                                                  --Howell.
      [1913 Webster]

            What schoolboy of us has not rummaged his Greek
            dictionary in vain for a satisfactory account! --M.
                                                  Arnold.
      [1913 Webster]

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"

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "rummage":
   beat, comb, conglomeration, disarrange, disarray, discompose,
   disorganize, disrupt, disturb, domiciliary visit, dragnet, examine,
   exploration, forage, frisk, hash, hotchpotch, house-search, hunt,
   hunting, jumble, jungle, litter, look all over, look everywhere,
   look through, mash, mess up, miscellanea, miscellany, mishmash,
   mix up, muddle, odds and ends, patchwork, perquisition, poke,
   posse, potpourri, probe, quest, rake, ransack, ransacking, rifle,
   scour, scrabble, scramble, scrounge, search, search high heaven,
   search party, search warrant, search-and-destroy operation,
   searching, shake, shake down, stalk, stalking, still hunt, toss,
   tumble, turn inside out, turn upside down, turning over