From HomoExcelsior

1. The surface generated by a straight line intersecting and moving along a closed plane curve, the directrix, while remaining parallel to a fixed straight line that is not on or parallel to the plane of the directrix. 2. The portion of such a surface bounded by two parallel planes and the regions of the planes bounded by the surface. 3. A solid bounded by two parallel planes and such a surface, especially such a surface having a circle as its directrix. 4. The chamber in which a piston of a reciprocating engine moves. 5. The chamber of a pump from which fluid is expelled by a piston. 6. The rotating chamber of a revolver that holds the cartridges. 7. Any of several rotating parts in a printing press, especially one that carries the paper.

---