frustum

American  

[fruhs-tuhm] / ˈfrʌs təm /

noun

Geometry.

plural

frustums, frusta

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

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

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frustum British  

/ ˈfrʌstəm /

noun

1. geometry

   1. 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

   2. the part of such a solid contained between two parallel planes intersecting the solid

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

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Etymology

Origin of frustum

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

Example Sentences

Figure 2.42 A frustum of a cone can approximate a small part of surface area.

From Textbooks • Mar. 30, 2016

Figure 6.44 Calculating the lateral surface area of a frustum of a cone.

From Textbooks • Mar. 30, 2016

Let r1 and r2 be the radii of the wide end and the narrow end of the frustum, respectively, and let l be the slant height of the frustum as shown in the following figure.

From Textbooks • Mar. 30, 2016

Figure 6.42 A frustum of a cone can approximate a small part of surface area.

From Textbooks • Mar. 30, 2016

The perpendicular distance from the base of a figure to the summit, or to the side parallel to the base; as, the altitude of a triangle, pyramid, parallelogram, frustum, etc.

From Webster's Unabridged Dictionary by Webster, Noah