cylindroid

plural cylindroids

1. geometryA cylinder with elliptical cross-section.

   1 more example

   The intrados of a simple vault is generally formed of the portion of the surface of a cylinder, cylindroid, or sphere, never greater than that of half the solid; and the springing lines of the coussinet, which terminate the walls from which the vault rises, are generally straight lines, parallel to the axis of the cylinder or cylindroid.

   1830, Sir David Brewster, The Edinburgh Encyclopaedia, page 523

2. geometryA certain three-dimensional surface described by a moving straight line, used to illustrate the motions of a rigid body and the forces that act upon it.
3. medicineA ribbon-like mucous cast frequently found in the urine in cases of mild irritation of the kidney.