tailboard

noun

1. A hinged board or hatch at the rear of a vehicle that can be lowered for loading and unloading; a tailgate.

   “She got one knee up under him and hurled him off, and was over the tail-board in a flash, landing on her feet like a cat, and panting hard, by the sudden release of a violent emotion.”

   “The man in the very new overalls was just heaving a box up on the tailboard.”