1) Can be lowered for loading 2) Gate 3) Station wagon feature 4) Tailgate 1) Endgate 2) Tailgate 
Portion at rear of fire engine where firefighters could stand and ride (now considered overly dangerous), or step up to access hoses in the hose bed.
• (n.) The board at the rear end of a cart or wagon, which can be removed or let down, for convenience in loading or unloading.
Tail'board` noun The board at the rear end of a cart or wagon, which can be removed or let down, for convenience in loading or unloading. 
A tailboard is the board at the rear end of a cart, wagon or other vehicle, which can be removed or let down, for convenience in loading or unloading.