Wiktionary
n. (context dated English) A leather strap supporting the body of a carriage, and attached to springs or serving as a spring itself.
Usage examples of "thoroughbrace".
When they had mended the thoroughbrace we filled the two boots again, but put no mail on top, and only half as much inside as there was before.
The thoroughbrace coach, tugging up the steep grade, would announce itself with a triumphant blast of the horn.
It was framed of steam-bent ash, fitted with laminated panels made of poplar or basswood, resting on thick leather straps called thoroughbraces, made from ox hides instead of steel springs.
The sounds of thoroughbraces groaning beneath heavy weight, the rise and fall of hooves, the lurching rock-and-sway of movement, a distant mutter of human voices.
As the heavy vehicle rocked on its thoroughbraces and a ground wind whipped away its dust, Dempster wrapped his reins around the brake handle and yelled a greeting to the peg-legged man in shabby denims who had appeared, bareheaded, in the barn entrance.
It was framed of steam-bent ash, fitted with laminated panels made of poplar or basswood, resting on thick leather straps called thoroughbraces, made from ox hides instead of steel springs.