the.com/lumber

means Timber that's been sawn into usable boards, or, as a verb, to move in a heavy, clumsy, plodding way.

from These are actually two tangled-together words. The 'heavy, clumsy movement' sense likely relates to 'lumber' meaning cumbersome junk — old furniture, junk, or pawned goods stored out of the way, possibly tied to 'Lombard,' since Lombard merchants in England ran pawnshops full of stuff cluttering up back rooms. The 'sawn wood' sense, mainly American, grew from that same 'stored junk' meaning: timber piled up and stacked in yards eventually just became known as 'lumber' itself, job and all.