- 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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for frustum
Wa'al, jest cut off the top, and what's left will be the frustum.The Light Keepers
Then follows, in most textbooks, a theorem relating to the volume of a frustum.
The top of the piston forms the frustum of the cone and the pistons are 110 mm.Aviation Engines
Victor Wilfred Pag
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
This leads to the corollary concerning the lateral area of the frustum of a regular pyramid.
- 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
Word Origin and History for frustum
1650s, from Latin frustum "piece broken off," from PIE *bhrus-to-, from root *bhreu- "to cut, break up."
Online Etymology Dictionary, © 2010 Douglas Harper