Definition of free piston
: a combination of two pistons that are usually of different diameters, are rigidly attached to the same piston rod, work in different cylinders without external connection, and are used in some pumps and pressure gauges
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Seen and Heard
What made you want to look up free piston? Please tell us where you read or heard it (including the quote, if possible).