Definition of "buckboard"
A simple, distinctively American four-wheeled horse-drawn wagon designed for personal transport as well as for transporting animal fodder and domestic goods, often with a spring-mounted seat for the driver.
Quotations
When he turned his head, aiming for a last look at Brother, turned it as much as the rope that connected his neck to the axle of a buckboard allowed, and, later on, when they fastened the iron around his ankles and clamped the wrists as well, there was no outward sign of trembling at all.
1987, Toni Morrison, Beloved, New York: Vintage, published 2004, page 106