Tumbledown describes something, usually a building, that's falling apart or on the verge of collapsing. A tumbledown shack might have holes in its roof, cracked walls, and a door hanging crooked on its hinges. A tumbledown barn might lean to one side, its wood weathered gray and splintering.

The word captures that sense of barely holding together, like a structure that could tumble down at any moment. You might read about explorers discovering a tumbledown cottage deep in the woods, or pioneers sheltering in a tumbledown cabin during a storm.

While tumbledown almost always describes buildings, it occasionally appears in descriptions of other structures, like fences or bridges, that are decrepit and crumbling. The word paints a vivid picture: imagine a house so old and neglected that it looks like a strong wind might knock it over, with shutters dangling loose and floorboards that creak and sag underfoot. There's something a bit picturesque about the word, too, as if the structure has stories to tell about who built it and the years it has weathered.