To move up and down or in and out like a piston.
A solid disk or cylinder that fits inside a hollow cylinder, and moves under pressure (as in an engine) or displaces fluid (as in a pump)
A valve device in some brass instruments for changing the pitch
To force.
Device used with muzzleloaders to push the projectile up against the propellant.
Ranch or trail foreman, usually the first or second person in charge. The person responsible for getting the work done.
An erect penis.