Device or system that helps reduce the force the driver must exert against the brake pedal. May be hydraulic or electric. Found on https://www.encyclo.co.uk/local/22335
A horseshoe-shaped add-on sometimes used on older mountain-bike rim brakes to increase braking power by eliminating flex from the brake posts (what the brakes mount to). Found on https://www.encyclo.co.uk/local/22515