frus·tum 
(frŭstəm)
(frŭstəm)n. pl. frus·tums or frus·ta (-tə)
Mathematics
Mathematics
The part of a solid, such as a cone or pyramid, between two parallel planes cutting the solid, especially the section between the base and a plane parallel to the base.
[Latin frūstum, piece broken off.]
frustumfrustum of a pyramid