noun
- cylindrical components that move up and down inside engine cylinders to compress fuel and air mixtures and transfer power
Usage: mechanical engineering; automotive
Examples
- The mechanic replaced all four pistons in the car engine.
- Steam engines use pistons to convert steam pressure into mechanical motion.
- The pistons move rapidly up and down during engine operation.
- A cracked piston can cause serious engine damage.
- The motorcycle’s pistons were firing perfectly after the tune-up.
- Large diesel engines may have pistons the size of dinner plates.