frustum

[ fruhs-tuh m ]

/ ˈfrʌs təm /

the part of a conical solid left after cutting off a top portion with a plane parallel to the base.

the part of a solid, as a cone or pyramid, between two usually parallel cutting planes.

Origin of frustum

1650–60; < Latin: piece, bit; probably akin to Old Irish brúid (he) breaks, Old English brȳsan to crush

A stick of timber is in the shape of the frustum of a square pyramid, the lower base being 22 in.

The Psychology of Arithmetic |Edward L. Thorndike
The lodge, therefore, was not a perfect cone, but the frustum of one; and in this it differed from the lodge of the Comanches.

The White Chief |Mayne Reid
Then follows, in most textbooks, a theorem relating to the volume of a frustum.

The Teaching of Geometry |David Eugene Smith
If the upper base is equal to the lower base, the frustum becomes a cylinder, and still the proposition remains true.

The Teaching of Geometry |David Eugene Smith

When they had reached the frustum's base, Urim descended and, in turn, presented various members of his retinue.

Warrior of the Dawn |Howard Carleton Browne

frustum

/ (ˈfrʌstəm) /

geometry

the part of a solid, such as a cone or pyramid, contained between the base and a plane parallel to the base that intersects the solid
the part of such a solid contained between two parallel planes intersecting the solid

architect a single drum of a column or a single stone used to construct a pier

C17: from Latin: piece; probably related to Old English brӯsan to crush, bruise