Lum·ber n.
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.
dimensional lumber, lumber, usually of pine, which is sold as beams or planks having a specified nominal cross-section, usually in inches, such a two-by-four, two-by-six, four-by-four, etc.
lumber room
n : a storeroom in a house where odds and ends can be stored
(especially furniture)