资料来源 : Webster's Revised Unabridged Dictionary (1913)

Lumber \Lum"ber\, n. [Prob. fr. Lombard, the Lombards being the
   money lenders and pawnbrokers of the Middle Ages. A lumber
   room was, according to Trench, originally a Lombard room, or
   room where the Lombard pawnbroker stored his pledges. See
   {Lombard}.]
   1. A pawnbroker's shop, or room for storing articles put in
      pawn; hence, a pledge, or pawn. [Obs.]

            They put all the little plate they had in the
            lumber, which is pawning it, till the ships came.
                                                  --Lady Murray.

   2. Old or refuse household stuff; things cumbrous, or bulky
      and useless, or of small value.

   3. Timber sawed or split into the form of beams, joists,
      boards, planks, staves, hoops, etc.; esp., that which is
      smaller than heavy timber. [U.S.]

   {Lumber kiln}, a room in which timber or lumber is dried by
      artificial heat. [U.S.]

   {Lumber room}, a room in which unused furniture or other
      lumber is kept. [U.S.]

   {Lumber wagon}, a heavy rough wagon, without springs, used
      for general farmwork, etc.

资料来源 : WordNet®

lumber room
     n : a storeroom in a house where odds and ends can be stored
         (especially furniture)