lumber
n. uncountablen. wood that has been cut into boards or planks to be used for building things. You usually buy it at a hardware store when you want to build a house or a fence.
n. timber sawed or split into planks, boards, or other structural pieces of standard dimensions. Refers specifically to the processed material rather than the standing tree.
We bought some lumber to build a new deck.
The construction crew arrived early in the morning to unload a massive shipment of lumber for the house frame.
Due to recent supply chain disruptions, the price of premium lumber has fluctuated wildly, impacting the profitability of small-scale furniture manufacturers across the region.
Exact origin unknown. The earliest recorded reference for the noun was to heavy, useless objects such as old, discarded furniture. Perhaps from the verb lumber in reference to meaning "awkward to move"; Online Etymological Dictionary thinks this may derive from the same root as lame. Possibly influenced by Lumbar, an obsolete variant of Lombard, the Italian immigrant class known for being pawnbrokers and money-lenders in early England. Compare English lumpish.
Uncountable when referring to the material in general; occasionally countable in technical contexts to refer to different types or grades of wood.