cylindroid

n. [ Gr. ky`lindros cylinder + -oid: cf. F. cylindroïde. ] 1. A solid body resembling a right cylinder, but having the bases or ends elliptical. [ 1913 Webster ]

2. (Geom.) A certain surface of the third degree, described by a moving straight line; -- used to illustrate the motions of a rigid body and also the forces acting on the body. [ 1913 Webster ]