[ fruhs-tuhm ]

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

Words Nearby frustum Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use frustum in a sentence

  • 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
  • The others amused themselves all around me; I found my delight in the frustum of a pyramid.

    The Life of the Fly | J. Henri Fabre
  • The form of the stand is the frustum of a hexagonal pyramid reversed, about six or eight inches in diameter.

    The History of Sumatra | William Marsden
  • Of course, when I was taught how to measure a cone, I was also instructed to do the same with the frustum of one.

    The Boy Tar | Mayne Reid
  • At ferrum, quod pluit in Taurinis, cuius frustum apud nos extat, qua ex fodina sustulit nubes?

British Dictionary definitions for frustum


/ (ˈfrʌstəm) /

nounplural -tums or -ta (-tə)
  1. 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

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

Origin of 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