brake block

Noun

 * 1)  One of two small blocks fitted to a brake caliper, which rub on the wheel rim when the brake is applied.
 * 2)  A block fitted to locomotives or rolling stock, which rubs on the steel tyre of the wheel when the brake is applied.
 * 3) A block (perhaps wooden) used for braking a horse-drawn vehicle.
 * 1) A block (perhaps wooden) used for braking a horse-drawn vehicle.
 * 1) A block (perhaps wooden) used for braking a horse-drawn vehicle.