A more thorough explanation:

Definition: A moving part is a component of a machine or apparatus that works together with another part to produce the intended result. The movement of the part is necessary for the proper functioning of the machine.

Example 1: In a car engine, the pistons are moving parts that work together with the crankshaft to convert the energy from fuel combustion into mechanical energy that powers the car.

Example 2: A sewing machine has many moving parts, including the needle, the thread take-up lever, and the feed dog. These parts work together to create a stitch in the fabric.

The examples illustrate the definition of moving parts by showing how they work together with other components to produce a desired result. In both examples, the movement of the parts is essential for the proper functioning of the machine. Without the moving parts, the machines would not be able to perform their intended tasks.