frustum

[fruhs-tuh m]
noun, plural frus·tums, frus·ta [fruhs-tuh] /ˈfrʌs tə/. Geometry.
  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.

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

Historical Examples of frustum

  • Wa'al, jest cut off the top, and what's left will be the frustum.

  • Then follows, in most textbooks, a theorem relating to the volume of a frustum.

    The Teaching of Geometry

    David Eugene Smith

  • 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 Teaching of Geometry

    David Eugene Smith


British Dictionary definitions for frustum

frustum

noun plural -tums or -ta (-tə)
  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

Word Origin for frustum

C17: from Latin: piece; probably related to Old English brӯsan to crush, bruise
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for frustum
n.

1650s, from Latin frustum "piece broken off," from PIE *bhrus-to-, from root *bhreu- "to cut, break up."

Online Etymology Dictionary, © 2010 Douglas Harper