The term WAGON PART can be broken down into two crossword solutions: AXLE (4 letters) and WHEEL (5 letters). An AXLE is a shaft that connects two wheels of a wagon, cart, or other vehicle, allowing them to rotate together. A WHEEL is a circular object that rotates on an AXLE, providing the means for the wagon to move. Both axles and wheels are essential components of a wagon, and without them, the wagon would not be able to move.