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 strike with a truncheon.
A short staff, a club; a cudgel.
A baton, or military staff of command, now especially the stick carried by a police officer.
A penis.